I wonder if I'm the only one wanting this, or if I'm just bad at searching, but I cannot seem to find any halfway decent phone that is roughly the size of the 1st gen iPhone SE.
The old iPhone SE was 124mm tall and had 2GB RAM + 64GB ROM in the most popular model.
Putting that into GSMArena tells me that there hasn't been any suitable phone released since 2016.
https://www.gsmarena.com/results.php3?nHeightMax=125&nRamMin=2000&nIntMemMin=64000
Why is there such a big hole in the market here?
Or maybe there is. The iPhone 12 Mini was just announced and will be released this month. It is nearly the size and form factor of the original SE.
Other than that, my guess is you'll be looking at phones for third-world and ultra-low-budget markets.
Pretty comprehensive review linked here: https://www.youtube.com/watch?v=UxUDmGHl7Eo