1. I believe that one of the main reasons why wallets get hacked is connecting wallet to a platform for way too long, some users even forget to disconnect the connection after.
Solution
Why haven't we seen crypto wallets that disconnect from platforms on their own after minutes of inactivity, it's easier for users to forget to disconnect after successful trans.
2. Not every crypto users are tech savvy and most don't even know how to keep their keys safe till date, writing recovery seed down or carving on a stainless steel or wood is still risky , either a hot wallet or hardware wallet keeps your keys is a necessity, I believe that we still need some work on here, making safeguarding keys easy still have a long way.
While I agree that (at least some) wallets could become more newbie friendly, your problem is not about the wallets imho, it's about how stupid the users are.
[1]
Connecting a wallet holding significant amounts of coins (as value) to a platform to gain a couple more cents is usually a bad idea.
Using the same wallet for holding life changing amounts and for daily operations is usually a bad idea.
I will add that many keep thousands of dollars worth on exchanges and web wallets instead of investing 100$ in their security and buy a hardware wallet.
[2]
Not all users are tech savvy indeed, but just imagine - for analogy - that there are some who give to unknown people all their credit card information, including the CVV code and so on, then they are surprised people steal their money (and please don't say 3DSecure is not avoided by some websites).
Now this same thing happens with crypto wallets, at a larger scale. Is the wallets' fault or is it users greed and stupidity?
So yes, you may have some points, but pointing a finger to the wallets is incorrect / not fair. Some may want to improve in a way the users understand better what they do, but they cannot do miracles. Also keep in mind that the best bitcoin wallets are free / open source projects, hence the developers work for free there.