The Cinque Terre is another victim of chronic over tourism. I made the mistake of taking visitors there some years ago. It was hell. It has got even worse after Covid.
If you get off the train two stops down the line, you can have a pleasure of enjoying a Ligurian fishing village without the caos.
You are correct about the selfie routine. Several times I have been doing photography in a monument and have seen people arrive take a selfie and walk out. Five minutes seems to be the average time these days that people spend visiting a place. Or those who arrive take a selfie, and then stand ages posting to Social Media, and then walk out.
Tourism seems to be more about boasting about the places you visit on Facebook these days.