I started out as a React developer and have been radicalized when I wanted to optimize my hobby website to run on crappy mobile data. The thing sends 3MB of Javascript on every full page refresh. I am now learning jQuery.

But isn't that what we want? Would you prefer that e.g. bridges used custom hand-crafted screws in weird diameters instead of standardized, cheap, proven off-the-shelf parts?

Everyone doing their own non-standard thing is e.g. why international train travel in Europe sucks. There's 6 different voltage/frequency combinations for high-level rail in Europe alone and dozens more for local systems. There's more than 20 incompatible train control systems as well. Running an international train service might require changing locomotives on every border crossing, because of garbage like that.

Standardization is a good thing.

Those giants make up half of the mess.