Just two color you have show lands, pain lands, fast lands, shock lands, tangos, check lands, shadow lands, filters, fetches, tainted and possibly some others depending on the color pairs. Then add in command tower and other viable "any color" lands (which is nearly as large a list). At the very least, the ravnica bounce lands, manlands and scry lands are entirely playable as tap lands.

Assuming you want to stick around ~15 basics with ~10 lands that add to both that only leaves a few slots for utility lands that aren't fixing. I'd honestly say 10 lands that add both colors is potentially too much in a two color deck. The majority of cards require 1-2 on color costs and you'll generally have more in the way of non land color fixing. While it's nice to not have to care about colors it's really not necessary to really push the limit unless you have a very aggressive mana requirement in the first few turns.

SOME color pairs are screwed out of some duals since there are cycles that weren't completed but anything with green, white (search) or black (tainted cycle/search) are fine. That basically leaves Izzet which is generally more concerned with quantity of mana over quality of mana.

In EDH, if your deck doesn't function without ABUR duals, your deck doesn't function. Blaming mana problems on not owning expensive lands is such a sad crutch. If all else fails, just run more lands.

People on this forum are probably less greedy on average than more casual players, and many still talk about running 36 lands in a format where you should really have at least 40 (plus mana rocks.)