Why are Dragon Age releases so broken on Deck?

I don't understand why Origins through Inquisition can't be re-released in a single, sensible, playable format like Mass Effect Legendary,* which works beautifully. Consistent connection to the Keep across the games, no broken links, with full Deck/Linux compatibility. Why is that difficult? Please, EA. I bought a Steam Deck because it was a cost-effective alternative to the full gaming PC I'll never be able to afford, and I pretty much just want to play Dragon Age, right now. Links in Origins are broken. Gamepad compatibility is rotten. Gamepad connection in Inquisition is non-existent (it ALMOST works with native Proton tools 😭). I've been fighting with it for weeks. I'm tired of experimenting with 3rd party stuff that doesn't work, and I'm admittedly more than a bit devastated. I just want these to be playable games. Please.

* (Editing to say that I'm not asking for a remaster. We don't want or need it. I just want the games to be normally functional and playable. 🙏)