A common man is born into the fiat system and is taught by his parents, friends and colleagues how to use it. Bitcoin is still new if we compare it with fiat and is slowly getting adopted. Give it some time and it will be simple to understand in the future than in the current time. The children of El Salvador will be far much educated with Bitcoin and the tech than those children in counties where Bitcoin is still a mystery for most of the population.

A child who hasn't learned how to ride a bicycle will tell you that it's very difficult, while the one who has been riding for months will tell you it's very simple. We all came into this world to find fiat currency as a major/general means of exchange. We had no choice but to accept it, and we didn't even bother to understand its technicalities and everything that happens behind the scenes. If I were to conduct a survey by presenting the mapping that appears in this thread to 20 different people, I don't think one person could explain everything. Isn't there already a complication?.

Personally, I don't understand everything written on that map, but I can choose to understand it just by my decision.

Just as Bitcoin has its own technicalities, fiat currencies also have their own, filled with corruption and centralization that only the issuers of these currencies can see, which is clearly unlike Bitcoin.

Bitcoin has its own technicalities, I won't deny that fact, but that doesn't stop anyone from learning how to perform a basic transaction by just copying and pasting an address, then inputting a specific amount. Moreover, some wallets are as simple as possible making it very easy to learn.

So, I think those people who think Bitcoin is complicated are only referring to the technical part, which I don't think they must learn if they are not willing to. Just learn the basics, like how to buy, make transfers, etc., because that's what we literally do with fiat currency.

Let's stop paying attention to these people who are not willing to learn, just like a child who is not willing to learn how to ride a bicycle, but make a complain of it's difficulty.

What Findingnemo is saying is that using fiat money doesn't mean you understand how it works.

Looking at the diagram, fiat system is really complicated but one don't have to understand that to spend fiat.  While Bitcoin system might be a little less complicated, many people are still baffled at how to create a single transaction with it.

Spending fiat is not as complicated as sending Bitcoin.  A person can transact with fiat currency with cash and outright hand over the money to the seller without waiting for the validation and confirmation of the transaction.  While a person who wants to use Bitcoin for a transaction needs a gadget, and application for the transaction and needs to wait around 10 minutes for the transaction to be confirmed if the deal is done through P2P.

With that many see paying with Bitcoin as way more complicated than just handing over cash to seal the transaction.  Since fiat currency can be spend anywhere, it is way more convenient and simple for a person to spend it than BTC.

Uhmm.. The Bitcoin and Fiat systems are both complicated; what makes people complain about the protocols in bitcoin is that they had to learn about the new system. Secondly, the decentralization makes everything under your own control...in a broader sense, you're entitled to perform every action that the banking systems and third party does, which makes it more complicated.

Just imagine a situation where you made a transaction with a lower fees and it got stuck for sometime; you'd have to manually pump the fees ... That's gonna force you into learning how to RBF or CPFP. Meanwhile in the Fiat systems, all you gotta do is visit your bank branch and the customer care would do the rest.
Edit:
It's actually good to learn things the hard way atimes.

Exactly his point, to even buttress what he said, there is no point in know some of the technicals of the bitcoin network if you just want to be mere user and not something like a developer or even node user. All you need is understanding the concept of how to set up your wallets properly, how to send your funds properly; knowing the required amount of fees to pay, when to bump your transaction and other little details, which are what the fiat currency also does. Things like how can you get to have collision with seed phrase are not that so necessary.

I only see people bring about the complexity of bitcoin technology as a whole propaganda to either shy away from using it or spread FUD and nothing more

Economist Saifedean Ammous, who wrote the book "Bitcoin Standard," which explains the deeper economic and technical aspects of Bitcoin, has also written "Fiat Standard," where he explains the fiat system. I believe these two books are essential reading for anyone who wants to understand Bitcoin and how the fiat system works.

It is just some people's excuse to say that bitcoin is complicated and this people are either too lazy to learn about bitcoin or have the opinion from other people. if bitcoin is legal and it is something that everyone born is introduced to as a normal thing, people will actually learn about it and not complain about any form of complication. The reason why people still complain about complication is that, bitcoin is not yet  accepted and the resources that make this information less complicated are not available to everyone.

Because of the habit of using fiat and people think the bitcoin system is complicated, we were born from an environment of people who use fiat so it is natural for people to say the process is complicated. But what needs to be underlined is that nothing is complicated if people want to learn and they can learn to understand. The growing technological journey will make it easier for people to understand the bitcoin system and now there are many people who know technology so that it can help understand the bitcoin journey system.

Technology used to be very limited and only a few people had access to the internet but now we can see bitcoin adoption becoming more widespread. This is due to easy access, the internet and increasingly developing technology. The point is that every new thing needs to be learned and nothing is difficult when people want to learn to understand.

In my opinion, the fiat system has many complications that ordinary people do not know about. We have only used the fiat system since we were born and most of us don't know about this system and how they control it. But Bitcoin is a new payment system and people are curious about it, and I believe that in the coming years, the blockchain and bitcoin system will destroy the fiat system.