Robert Smith is not in great shape, yet he sings and plays guitar for four hours, and his voice is stellar. Seriously, it's a fucking miracle. He's a year older than Bono too.
If we're going to talk about old guys and stamina though the winner is clearly RUSH. Over three hours of complex material played every night, though those days are probably over because Peart feels he doesn't have the physical ability to play up to his standards.
The average set for Nick Cave & TBS over the last few years is 17-19 songs.
Depeche Mode average 22 songs on their current tour, and Dave is more active than Bono (also in better voice, too). Martin takes a few songs though.
New Order average 16 songs over the last few years.
Soundgarden
averaged 16 songs this year (but all more demanding than any U2 song)
Paul Weller has a 32 song set right now. He wins.
U2's sets are pretty normal for a band their age. Weller, Rush, the Cure, PJ are exceptions.