I'm certainly not a top 1% athlete. I might be top 1% in athleticism, but if you're restricting to athletes... Definitely not. There is no way I could make the same progress at home as I've been getting with my trainer for the past couple of years. Not a chance. Luckily he has a private gym where only one client is there at a time since covid times started, so I haven't had to test this.

But... Having your program tweaked constantly, form improved constantly, diet examined regularly, etc... Youtube isn't a substitute. And without equipment? With my trainer helping, maybe... With youtube? My fitness would definitely be worse.