As of 2021, VSCode is the king in text editor "industry". It's dominant in this market. The reason is high advanced customizability as well as being free.
VScode fits any coding environments,and it is a universal app that can run anywhere. I've been seeing a lot of people fail to refuse config-free/customizable text editor(VSCode) temptation.
Yes, I am writing this doc in VSCode.
Vim is a free software. I've been trying to get along with Vim, but I cannot call Vim the best friend yet.
https://github.com/junkpiano/nvim
Xcode is the only one IDE for MacOS/iOS application development.
When I do something for Android or Flutter, I am using Android Studio.