I think the biggest culprit is just that you have to work through 100 floors of fluff every time you restart. If you didn't have to start at 51F and could just start at 101F after having cleared 100F once, you'd shave a lot of time and frustration off right there. Probably not enough to fully overcome the problem of unreliable random people, but it would help.

FC and friends are generally the way to go, though. Have made multiple climbs with a couple different combinations, and we've just taken it slowly. At least with friends you can be more confident that even if something comes up and plans fall through one day/week, you can just get together the next day/week and carry on then.