I'm currently switching away from #telegram. Other than most people I don't simply delete my account.
First step was: Evaluating alternatives for my contacts. So I went for Riot and Signal as platforms I recommend for further communication.
Next step was making Telegram low priority. Disabling notifications on my phone, remove the desktop app.
Now I make it less accessible. Removing it from my home screen.
As soon as I make it to backup my messages I'm going to delete it.