Are there solid existing launchers that can be swapped in? Changing the launcher is one of the first things I do when I get a new Pixel phone and highly recommend it, but I don't really want to have to maintain a vibe coded one.

I've used Projectivy for years on every Google TV stick I own (Google/Onn). Works perfectly with full customization/zero ads on the free version and has a workaround to take over the Home navigation to bypass the built-in launcher without ADB or rooting. I chip in for the premium version to help out the dev since I get so much value out of it but the freemium features are mostly just cosmetic and the free version has everything you need.

Projectivy seems good and I use it on cheap android / Google TV devices since learning about it last month.

I tried projectivity launcher on one of these and it seemed reasonably good.