You could also view the old version of reddit "old.reddit.com", however editing URLs like that is a pain to do on mobile. Very frustrating if I am looking for information on my phone and what I am looking for is on Reddit.
The reddit app used to but they are pushing everything into the new media player (including photos) and it takes you into algorithm content hell. Not even restricted to your subs.. just whatever they want to throw at you. It is enough that I cannot use the reddit app anymore (or hardly use it).
On iOS you can make a shortcut to find/replace www with old in the url. I imagine there's a similar tool for Android, but someone else will have to make that recommendation.
The Firefox addon is called Old Reddit Redirect ... but there is also Redirector which is a more generic redirector, for any websites and patterns. But to be able to use them on Firefox Android, you have to use an addon collection.
I use Teddit a lot but found the original "teddit.net" performance to be quite poor, especially during peak US hours. It takes a lot of time to load more niche subs that aren't cached and video playback is stuttery.
I generally prefer teddit.adminforge.de, which uses the same Teddit code but runs on a much less loaded server and thus performs much better.