Although it has lead to every website have that 2/3/4 column look for about 10 years at least. Widescreen monitors have 50% of the space wasted,

I think it was Grid that started it, had 12 columns you could divvy up with a load of weird classes, and then a version of grid got added to the CSS standard instead so now it's just there.

You can still make CSS from scratch, but I can see why a beginner would go with Bootstrap or whatever.