You can do lots of things with both, but that doesn’t necessarily mean you should.

People have used Lutris for other apps because it was a more convenient wrapper for Wine than the defaults offered but it’s not primarily designed for it and support will be limited. Lutris is designed to be a games library and that’s it’s focus.

I personally wouldn’t recommend wine newbies to be using Lutris to run everything because if nothing else it would be annoying for the Lutris dev team to be dealing with “I can’t get Microsoft Word working”.

I also personally wouldn’t recommend Bottles for games because of all the other features Lutris offers. I have a huge library of games and I wouldn’t want to manage that in the Bottles interface. But I’m aware people use it for that and Lutris is one of its supported runners.

Bottles and Lutris complement each other and work together well. But lutris is designed to be a games libaray while Bottles is designed to be for everything.

I personally use Lutris for games (most of my wine use) and Bottles for a few other windows apps.

But the real star of the show is under the hood - it’s wine and Proton doing the heavy lifting. Lutris and Bottles are tools to get the most out of them and it’s choice which you use and how.