While not an "app store" per se, Obtainium is pretty useful. It lets you manually import apps that you'd like to receive updates for, and can pull from different sources. For app discovery, I use Droid-ify.
I have found Obtainium to be quite unreliable and am surprised by how many people recommend it.
In my case it frequently fails to detect which version I have installed, fails to detect there is a new version, and even tells me an app is outdated when the version I have installed is higher than what it believes is the highest version. I currently use it only for 2 apps: Uazo's Chromium build (which is not on F-Droid) and Obtainium itself.
In case an app is on F-Droid I personally see no reason to get/update it through Obtainium.
Strange. I haven't encountered any major quirks with it in my use. I've had app gave me trouble but it was because I had installed a pre-release version of the app by mistake, but once I installed the correct version, it was fine.
I will say one criticism of Obtanium is that it's easy to get rate limited if you use a VPN, which is really annoying.
I find that Droid-ify handles up to 95% of my needs. Obtainium is good for 2 or 3 apps that seem to take forever on F-Droid. And once a week I launch Aurora Store to update some things like Contacts or Webview.
I really should give App Lounge more of a go...because it could replace Aurora and Droid-ify.
When I first heard about /e/ os, it looked a bit too weird, and I was too skeptical, but they're growing so nice and creating interesting tools. I think I will give the project a shot.
I was using F-droid until last week. Supposedly Droidify has a newer API and auto updates are supposed to work better, but I haven't noticed a big difference. I still have to go click "update all" as far as I can tell.
It would help if you mentioned what OS you're talking about in the opening post for others to assist you. Not everyone knows accrescent is an Android app.
Thank you for the feedback. I actually use every OS, so I'm interested in any security and privacy preserving app stores for every OS. I just happen to be going down the Android rabbit hole at the moment. Not to say I wouldn't be interested to hear where others are at on their journey. Cheers!