Quite a lot of people can do those around. For the internet there's a huge bias for stronger lifts cause videos with 1 plate squats or 25lb bench will A) not get posted. B)not get traction and likes (cause it's nothing special) and C) you yourself would ignore. Cause of the above two.

I've seen plenty of strong people at commercial gyms I've been to. Hell, even planet fitness. You're looking at the gym population through your lens which is a slice of a slice of that gym's membership count. Where you physically are inside the gym, your general awareness of the gym floor, what time you get there, what time the stronger members get there all play a role in you physically seeing those lifts happen.

I have seen exactly what you're referring to. 405lb+ deadlifts from 140-150lb guys(6plated deadlifts from bigger or stronger guys), 3plate + bench for reps, 4-5plate squats and I'm talking about commercial gyms not powerlifting gyms.