Ask HN: What is the most basic smartphone that will still run Signal?

My current phone (S9+) is just not cutting the mustard any more. It's too big and has too many features I never use. I wanted to switch to a dumb phone but from a security and privacy standpoint, it is not a great option. I am wondering what the most simple smartphone that will run Signal messenger since that is all I ever use my phone for, messaging and calling. I was thinking Nexus 5 but what experience do you have with other phones?