That's the problem. Building a heavier rocket is much harder than building a lighter one (see explosion above). So why not send a few lighter ones instead of a heavy one? This is what the launch market has concluded for a long time.
Disagree. The overall Starship system's problems are obviously in Starship, not in the Super Heavy booster. The latter is far heavier. But it only has to do 2 things well - sub-orbital launch, and sub-orbital precision return. And the launch tower's chopsticks give it a lot of help with the latter.
Vs. the Starship has to do far more things - all of them mission-critical - while being ruthlessly optimized for weight.
Let’s assume starship works out and they come up with a nifty wide-opening payload door solution, one of the advantages will be payload volume as well as mass - the JWST’s main mirror would have fit inside without being folded (although the heat shield would not have).