Brave is sketchy. Their whole "unblock ads to get rewards" thing doesn't sit right with me. The only companies that do that are those who are in bed with the ad companies.
I have yet to find an extension that didn't have a usable Firefox equivalent. But if you must stubbornly stick with Chromium, at the very least use Ungoogled Chromium and grab a script off of GitHub that allows you to still download and install extensions from the Chrome Web Store, as well as an auto-updater.