I recommend a used 6s or 7s (get the plus if you want bigger) or even newer if you must! Dirt cheap and my 6s plus is a great size. At first I thought it was way too big but now I think it is perfect, since it is great for reading and watching videos and surfing. I would have considered se if I didn’t have this hand me down from my daughter, but I agree, they are quite small.
Mine was in pristine condition when I got it and it still is except for the battery. But a year or so ago before the crazy inflation it was only $40 at apple for a replacement battery installed. Not bad atoll!
There is talk of potentially dropping updates, but I think 6s was still expected to be safe the last I looked. It is 64 bit so that helps. It might’ve been the plain 6 that is getting dropped.