How do you catch small product bugs that users quietly deal with without complaining?

It's super when customers quietly slip away and you have no idea why because everything looks fine on paper. Users hate filling out long feedback forms so they won't email support just to say a button layout is annoying they'll just quietly switch to something else. Hopping on quick user calls or looking at session replays always shows the tiny blind spots you completely missed.

What is your go to method for spotting those silent usability issues before people churn?