uBlock Origin works best on Firefox, according to the extension author. This is definitely a reason to use Firefox, and even more so when Chromium phases out Manifest V2 completely.
Your Samsung Galaxy Tab S5e has a PassMark score of 5488. I've been happy with the performance of Firefox on a Google Pixel 3a, which has a nearly identical PassMark score of 5483. Maybe your expectations or experiences are different, but I'm comfortable with saying that Firefox's performance is fine for me on a range of Android devices, old and new.