The real solution is to stop using transit to move human misery from one place to another. Get everyone an individual car (a self-driving at this point EV, of course) and redesign cities to be human-oriented, not transit-focused.
There is NO mathematical way to make buses robust. They will always be some combination of too slow, too expensive, or too inconvenient for most people.
Buses have low average speed because they need to stop often. And you can't make bus stops more infrequent, because people won't be able to walk from their homes fast enough. And doing complicated systems with local/express buses just wastes time during transit.
Buses can't be frequent, because the average daily load is already just around 15 people per bus. And this is with longer off-peak intervals.
Etc.