I used to use RiF back in the day when it was still a buggy mess. I don’t even remember when I moved to the native app. I don’t agree with Reddit’s policy update (why I’m here) but I thought the default app was fine for normal browsing. I never had issues with the video player or anything else.
I use Samsung Galaxy devices if that’s relevant.
I used it for viewing my hometown sub because it was easy to put a direct link to it on my home screen via the app. We went through a lot of covid lockdowns a few years ago and it became a valuable source of information and social interaction for me. I found it loaded posts much more slowly and some videos wouldn’t play at all. It actually seemed to get a little better recently (for me anyway) but still nowhere near as good as Infinity for Reddit which I used around 90% of the time. I use a cheap Android smartphone.