You can’t add on device storage but you can add anywhere from 50gb up to a whopping 12tb of cloud storage with iCloud+ For a monthly subscription of course, but the 50 and 200gb options are pretty cheap and reasonable

Lol get rid of it, get a newer phone with more standard storage trust me

If you are not storing videos and lots.of photos, why don't use it. So it all depends on your case what and how you use it. I don't agree with the "just chuck it" ideology, when it's still fine to make calls and surf the web and watch YouTube, etc. I use 2020 SE with 64GB, I still have 32GB free space. If I need space I have so many free choices, one drive, google drive, Amazon Prime photos offer unlimited photos storage....