Recently my iPhone 6s died but I'm not in a rush to buy a new smartphone. The particular SIM card installed is just a number mainly used to receive SMS TAC codes.
Digging my store I found an old phone bought in 2017. It's almost unscratched as it just saw light duty before I start using iPhone 5s. The SIM card from iPhone works fine with a cheap adapter and I was soon receiving SMS on the phone.
Call works fine as well but holding a tiny phone making call feels totally ridiculous these days. The screen refresh rate is slow but still usable for typing SMS and playing the on-board games.
Biggest issue is on the telco side. I've been using this Celcom number since 2009 and the coverage is excellent. However, I found that in certain areas there's no 2G coverage - only 3G & 4G. Usually this happen at shopping complexes and other high traffic areas such as LRT stations.
This is nothing new and I've spotted this issue back in 2017 but it wasn't as widespread back then.
In conclusion, using a 2G only Nokia works fine for my use case but it will be unwise for most people. I can't even give it to my daughter to use for outings and such.