If traders and holders can trade on Exchange in their wallet that they own the private keys it will reduce exchange hacks, I'm not talking about dex because this idea is better than DEX, I know some wallets like coinomi and atomic support insta swap using external platforms like shapeshift or uniswap kinda but just think about it
This is something I'm looking forward to, while many might think it's impossible I think it's damn possible, what do you think
I think various new wallets have this option of swapping and exchanging that you are talking about even trust wallet has that option but yes there are not many coins listed for this option so may be they need to work on that and add as many coins as possible, the ideal case scenario would be to add all coins and tokens that are tradable but then again it can not be as easy as it seems because not all coins have buyers and the wallet service has to sellthe coins to someone too.