Matt,
There were others in many of the gyms who could bench press 405 lb, deadlift 600 lbs, etc. Squatting super heavy 500 lbs or more was less common. You can't compare lifters with non-lifters when looking at how much people lift.
You are correct that there are others, but it would be a misnomer to suggest those numbers are common.
The numbers you claimed for yourself and your kid brother are extraordinary. Almost extraterrestrial, lol.
Surely, you'd have some idea that you were among the strongest men in your local area?

I agree that a 500+lb squat is particularly impressive. But all your stated numbers are, if true.
I have a sense of where I'm at. I'm my city [pop. 108K], as far as I can tell, there may be about 30 men who bench 315+ and deadlift 495+. But I've scoured this town, and have never found 50 at one time who do. And certainly not 108 [108 out 108,000 = Top 0.1%].
I can basically even list all the 700+ deadlifters in my city over the past decade:
[1] Maxime Boudreault [#3 @World's Strongest Man 2021].
[2] Kyle Rayner [#9 @North America's Strongest Man 2012].
[3] Luke Skaarup [#6 @Canada's Strongest Man].
[4] Dallas Hogan [#4 @ Ontario's Strongest Man 2007].
[5] Ben Thompson [Static Monsters Australia]
[6] Adrian Lesey [#5 Canadian Nationals SHW bodybuilder].
[7] Kris Hald [genetic freak - got to 800-lb in two years].
[8] Andre Vaillant [genetic freak].
[9] Adam Czinkota [genetic freak].
There's apparently one other young kid - only 21 - who deadlifts 700+, who I haven't met.
Keep in mind that this list goes back a full DECADE or more in my city.
I may be missing one. Maybe two. Maybe three. Certainly not more than that.
So when I say these things aren't common, I'm not stating my personal opinion - it's statistical fact.
On Getbig, these things are common - in reality they are not.
Photos below of Maxime Boudreault, Kyle Rayner, Adrian Lesey, and Andre Vaillant.