There are a lot of shitcoins that copied bitcoin and changed a lot of different variables including total supply and time between blocks. You selecting one out of hundreds makes no sense. Besides if LTC were any better than bitcoin then it would have been actually used as a currency while it isn't.

There's no point in comparing unused potential.  LTC might be technically capable of providing 4x the number of transactions BTC does.  But in practice, it handles roughly half the number of transactions BTC does.  Until a network is running at capacity for a prolonged period of time, you can't accurately compare how well it competes with Bitcoin.  

I could create a coin that can theoretically handle 20x, or even 50x, the number of transactions that Bitcoin does.  But if it only has a small handful of independent nodes and hardly anyone mining it, it's not going to be a secure network.  And if this new coin was running at capacity, the total size of the blockchain would be growing really quickly, which is not a good incentive for people to run nodes.  It would be centralised and would require trust when you use it.  That defeats the whole point of what satoshi set out to achieve.

And as for total capitalisation, that will impact the value of the coin.  This was something satoshi understood and was a factor in how many coins they settled upon.  Until you understand these factors, there's little point in discussing what satoshi "should" or "shouldn't" have done.

There were a lot of Bitcoin clone coins made, and probably more other will come. The only lucky part for Litecoin is that it was the first (99%) clone. The first ones still survive. If Litecoin would have been created this year, it probably would be dead already.
So Satoshi should have not done anything different. On the other hand, you should not preach about altcoins, since whatever you say, they are not Bitcoin. Not at all.

So, what does Bitcoin have to do with Litecoin's, of course, the transaction/miner block issue, has nothing to do with Satoshi.

Who created Bitcoin and who created Litecoin's, of course these two questions are far from your idea, if you know the quote below, maybe you are embarrassed to say that.

What you need to know is: Charlie Lee and Satoshi are different people, if there is no Bitcoin, make sure there is no Litecoin either.

Litecoin isn’t a global acceptable cryptocurrency then bitcoin yet, bitcoin is a most acceptable and usable cryptocurrency then all others.

Is it only because of this comparison that you have come to a conclusion? I don't think it's enough to just compare one or two points. Because all are built from different histories and you should know that. Matching it with Litecoin won't make everyone think in your line.

Are we still having this blockspace debate in 2021? Fine then.

84 million coins or 21 million doesn't really matter. Bitcoin would be 4 times cheaper and people would have 4 times more Bitcoin. Zero net changes.

4 times faster blocks means 4 times more blockchain bloat which means faster centralization of the network. And these 2.5 minute blocks would require less PoW so they would be less secure, so you would need more of them before you can trust a transaction, so the waiting time would be almost the same on practice.

Bitcoin can't be a world's currency neither at 7-11 transactions per second or at 28-44 transactions per second, it needs thousands of transactions per second to do it, like Visa does, and Lightning Network is the only way to achieve this.

Keep in mind that even multiplying the coin supply and reducing the average block time by a factor of "X" will still overload the network if a surge of users were to make transactions at once, which fiat payment processors can handle because they do not have such linear parameters, they can adjust these at runtime at will.

What OP has mentioned is true. In terms of transaction speed and low transaction fee with Litecoin. By the time we need to understand what is the reason for Litecoin to reach such a level. It is all because of bitcoin, if it had copied some other shitcoins now this could've never been known to the outer world. Particularly litecoin gained investment just because it is developed over the platform on which bitcoin is developed. So, it isn't fair to make Bitcoin inferior against Litecoin.

I don't think the number 21 million was randomly chosen by Satoshi, this number symbolizes something specific in Satoshi's mind, I don't know what it is but I'm sure it was intentional and not random, Bitcoin and Litecoin can be compared to gold and silver Gold can never beat silver on Launch also Litecoin can not beat Bitcoin one day, Litecoin appeared shortly after Bitcoin, but it could not one day compete with Bitcoin. Not only that, it could not compete with other coins like Ethereum. Look at its rank in the market over 10 years and you will see that.