JetBrains IDEs are very good indeed, and if they (or VSCode) work for you, you should use them. There's some features in these IDEs that are better than what's available with vim/tmux, and the other way around. In either case, with sufficient motivation, any feature can be implemented in the terminal, or in a good IDE. It pretty much comes down to how much your workflows are remote-based, how tied-in you are to a terminal environment in general, and personal preference (like not wanting to touch a mouse).

If you're used to IDE's it's doubtful you'll appreciate vim by "trying it out" for a weekend. The learning curve is much too steep for that. Conversely, if you've used vim and terminal tools on a daily basis for >15 years, you probably won't have much motivation to switch to GUI-based IDEs.