I went through the rabbit hole of seeking out open source wallets and honestly I don’t think I can recommend one that fits everything you’ve listed. Here are the ones I recommend though:
Coinomi: these guys are OGs and super trusted, and their desktop wallet supports many coins. However, it doesn’t seem like they’ve been as active in maintaining it recently and they also closed off a bunch of their code to help combat against scams and bad actors (or so they claim).
Exodus: their UI design is great and I’ve used them for a good while on mobile and desktop. They do support many currencies and networks, but they are closed source and at least their mobile app pushes quite a bit of garbage
Electrum/Electron Cash/ Electron Lite: these are open source wallets for Bitcoin, Bitcoin cash and Litecoin respectively, so they don’t support stable coins at all. They’re also meant for people who are familiar with the technical side of crypto so I’d recommend novices to avoid them. However, they are highly trusted and completely open source
Cake Wallet: open source but only support Bitcoin, Litecoin, and Monero. They just added Ethereum in their last update, but not sure if tokens are supported yet. Their desktop app is in beta so it’s not super stable yet but there is a lot less clutter than other apps
Anyway I hope this helps with your search. If you do find anything that fits your needs please update me because I’d like to poke around myself!