Perhaps users give more priority to the conveniences, such as when using exchange wallets, there is usually no need to store the Seed Phrase separately, similarly, there is no risk of losing the Seed Phrase, so maybe they consider exchange wallets safe to store their Bitcoin. Similarly, through exchange wallets, buying and selling can be done very easily and there is no need to transfer Bitcoin using a specific address. Maybe considering this overall issue, investors use such exchange wallets to maintain their investments for the long term despite the risks of using exchange wallets.
Exchange wallets are not safe, but as you said, some people prefer using it to avoid the stress of saving their seed phrase which is true for some people, while some people dont have the knowledge about the non-custodial wallet, so they go with what they know.
However, some of us here are using exchange wallets to receive payment from our various signature campaigns not because we are willing to hold our Bitcoin there, but maybe to receive it through exchanges and send the part they will invest on long term to their personal wallets, I dont know for others, but I think thats the reason for using exchange wallets for people like me.
We need to be responsible for our investments, keeping our seed phrase safe is part of responsibility if we want to be decentralized and dont rely on anyone to hold our Bitcoin. We are learning our lessons about these centralized systems everyday, I think we keep learning every day.
