Yep! It's not the same experience as F-Droid (e.g. it's not gonna be you scrolling through a list of apps, picking the one you want, and hitting install. Obtainium is more of a "get the URL to where the app's releases are, paste it in here, add it, then hit install, plus you might have to do a little config so it selects the right release if there are multiple", but once it's set up, it's set up.

I fully replaced the F-Droid app with Obtainium for actually installing and updating apps, but I still keep the F-Droid app around just because I can go on there, search up apps, do a little browsing, then take the app I want and put it in Obtainium.