It's kind of amazing to me that we can build 3nm chips but we still haven't figured out how to build a uF-range cap that has long MTBF, good overvoltage tolerance, low series resistance, and doesn't blow up.
Indeed. But... caps are improving, but slowly. The size difference between say a 100 uf 25V cap today compared to one from the 80's is considerable, and if you add another decade it is hard to believe it is the same component.
By contrast inductors have not changed in size at all and resistors are very much limited by power dissipation.
By contrast inductors have not changed in size at all and resistors are very much limited by power dissipation.