TV has always been around, pre-internet you still saw amazing people on TV, but the difference was that they were on TV, so you and your friends did not compare themselves as much to them, because the perception was "of course they are better than you, they are on tv", there was a barrier, it's like when the circus came to town and you saw the acrobats there, you might have play-pretended to do the things they did, but of course you didn't seriously compare yourselves to them.

The insidiousness of social media is that EVERYBODY is on social media, it's the same medium, there is no difference between a video shared by your friend and a video shared by an olympian or a world class musician or even an adult beginner that due to genetic blessings is learning things way faster than you, this breaks the wall between you and them and as much as it's good in some ways (pre internet you would never be able to have a discussion with a pro musician unless you personally knew them) it is bad in many others, leading people to misjudge what average is

It also does not help that so many people when discussing what they do always say that "if you want it enough and work hard for it you can do everything", which feeds into the "I am not as good as social media person X at doing Y, therefore I must not be working hard enough, what's wrong with me" while in the end to be at the top yes you need to work hard, but you need to be lucky to have the genetics to be there too.

If pre internet you saw 10 of your friends try something, you had a good idea what "average" was, and calibrated your self esteem accordingly: all of you being average, you all had something you were better at than the group, and something to fall back on to feel good about when you didn't do well at something else

Now all you see on social media is either the top of the field being so much better than you at everything that it feels impossible to be able to get from where you are to where they are, or average people made fun of because they "suck" (even if they are just average in the end), this IMHO is what's causing a lot of problems in terms of depression and general lack of happiness