Just a small correction, the founder of Segway is Dean Kamen who is still alive. It was the then-owner of the company who died.

Is there a modern segway? I mean, I find ebikes are probably a better option in general, but it seems like all the pieces to recreate the segway for a much lower price are there already.

Looks like the closest thing is the self balancing stuff that segway makes. Otherwise it's just the scooters.