I assume this might occur during your new days to the system, exchanges can not be relied on when we are thinking of investing for a long term and exchanges are always not the best option in times of investment no matter how long they have stayed in the system. One of the high risk is just what you mentioned now, they can get hacked and still go free without any consequences but when we hold our investments in a non custodial wallets then we will be free from exchanges hacked or maybe exchange vanish all of a sudden.
 However, non custodial wallets doesn’t free us from hackers totally but we get to stay safe as long as we don’t give out our seed phrase or maybe store them online. For a long term holding, non custodial wallet are the best to hold our tokens.

Online or offline, you must secure your wallets and wallet backups properly. If you do it badly in security, you will lose your wallets and bitcoins.

It's true to warn about risk of wallet backups online.
How to back up a wallet seed phrase?
Security checklist.

Not sure you want to talk about altcoins and expand your recommendation from Bitcoin to altcoins but if it's only your advice about Bitcoin, it's inaccurate and misleading information.

bitcoin is a native currency on Bitcoin blockchain, and it's a coin, not a token. A token does not have its blockchain but it is deployed on an available altcoin blockchain and uses that blockchain's native currency (an altcoin) for transaction fee.

If you haven't lost Bitcoin or crypto before it shows that you are a newbie or a beginner, there is no way that anyone in here can come out and say they have never lost anything and they are not a newbie.

I lost alot of money in alts too believing that the market was just getting  started, stupid me, I have read about similar stories on this forum too so I am not the only one  and today I've not even recovered 20% of the lost money.

Some of the coins are also dead, I learnt a big lesson and I hope that somehow I bounce back in the future, I am not giving up too and I hope everything works out better.

Here it is already mentioned about how few lost their bitcoin due to relying on exchanges. The same happens with me; I lost enough just because of this. Now I am still facing troubles because they never come back things are getting worse just because of this. I never trust any exchange; it always recommends everyone to have a wallet with their own control.
Usually things like this happen when newbies trust centralized exchanges too much and put their funds blindly. Hacks and freezing accounts are done by them, which are regular, and newbies have never been able to do things for recovery. I lost nearly 3 Bitcoins they hacked, and then few emails arrived, but they never put in any solid effort to give my money back.
My life was completely ruined due to this mistake with the lesson "Never trust any exchange" always stay safe.

The only time that I've been careless I guess when I've pressed that convert or swap button of our local exchange when I have no freaking idea that I was selling the ones that I've held before. Yes, a complete noob and that's okay because I've learnt from it already. But sending to a wrong address, never happened to me. And it's due to the unique wallet addresses that we have. Unless a PC is infected by that malware copy pasta virus and you don't cross check addresses before sending then that's the only possibility that someone will fall for it.

Totally agreed with you. Ignorance means lacking the knowledge of Bitcoin investment, while carelessness means not doing the right thing despite knowing what to do and before they realize it, they may have already lost some of their Bitcoin. That is why it is important for those who want to become investors to first of all acquire knowledge about Bitcoin through research before taking any action, because if they choose to invest in their own way without following the proper principles, this can lead them to make financial mistakes that can ruin them. And you know, there is no customer service to help restore Bitcoin once it is lost. In addition, I will say carelessness can sometimes lead to ignorance, as one can look for shortcuts to get what they want because of laziness.

Lack of understanding as well as carelessness also make the situation more difficult to control and I have felt both of these things at the beginning when I was in the initial phase when getting to know bitcoin. Error copying address, carelessness when placing assets on the exchange that actually turned into a disaster and the wrong choice in holding assets that should never have been done I have felt it but this is an experience that can actually be good because after I felt the loss due to carelessness and lack of understanding I became more careful when trying to trade etc.

If before I just copy paste the address when I want to send or receive something but now I pay more attention to this because one mistake makes the loss even though it is small but still we will regret it.
There may be some of us who have never felt this way but it's only a few of the vast majority who have ever felt this actually avoidable mistake.

OP, I've been the most careless person when it comes to this, this your experience has happened to me a couple of times, I had to locked my right address in my clipboard so that I won't make the mistake again but the interval of the mistake was close but still it was a $500 and $760 worth of mistake which pains me till now and another mistake u made a long time ago ago was when I lost my pass key to my butcoin investment when I started a long time ago

It happened to me too—luckily, it was only a few satoshis; i lost the wallet passphrase. As for transactions, i double-check the destination address carefully, and i frequently use escrow when dealing with new people.