You are wrong; centralized exchanges don't seize accounts of users who haven't passed their KYC verification. In some centralized exchanges, if you haven't passed your KYC verification, you can only withdraw a certain amount of bitcoin daily, and if you want to withdraw above that amount, that is where you will need to pass your KYC verification to enable you to withdraw any amount of bitcoin you want. While some centralized exchanges require you to pass your KYC verification immediately after you register on their platform before you can withdraw your bitcoin from their centralized exchange. What can lead anyone to lose his bitcoin on a centralized exchange is if the centralized exchange where the person keeps his bitcoin got hacked or when something bad happens at the backend without the person knowledge, such as when a centralized exchange is bankrupt. It's not your key, not your coin.
I just pointed at one aspect which can result in closure (or restriction) of your account at centralised exchange. While Satoshi Nakamoto presented concept of p2p fund transfer without any middlemen which makes you owner of your assets unlike what's going on in banks. There are rules of centralised exchanges, if someone is happy to follow these rules then he may join the centralised exchange. To me it's best that I have control of my Bitcoin keys rather then somebody else controlling my Bitcoin keys.
You may also want to keep a back up of your wallet, and you also might want to have instructions for heirs in the event of your death. These are not easy questions or problems to solve, to the extent that you might either want to make sure you don't lose your seed words due to some kind of natural disaster (fire or something), and that you have some preference to passing your coins to heirs rather than dying with them.
There won't be any attorney that will distribute your bitcoins to your next of kin after your death, one has to do it himself. There are lot of bitcoin lost forever because of owner losing the keys or due to death of owner. This is something one has to take very seriously, if you have Bitcoins then you must inform your next of kin how to use them after your death. Make sure your hard work is not wasted once you leave this world.