Colonoscopies are a great example. As their use increases past a threshold more people are injured by additional surgery than you actually help. This is again at a population level.

There's no free lunch here.

Then wouldn’t these be left alone ?

The more research and procedures done the more info gathered on the evidence

At a population level its well established that beyond a certain point you're injuring more people than you are helping by doing the colonoscopies at all. Where to draw that line is where the debate is playing out. The problem is well known, and I'm not aware of ANYONE seriously suggesting that it's possible to eliminate this problem.

The problem is that you don't know which ones would never develop into anything if left alone.

The reason they're left alone now is that you don't know they're there, because you never do any test that shows them being there.

But once you do a test that shows that something is there, it's a lot harder to just leave it alone. Something is there, and you don't know that it's never going to be a problem, so you end up not leaving it alone.

If you were going to leave the thing alone anyway regardless of what the first test showed, there's no point in doing the first test at all.