The number of riders who actually need a triple is getting smaller and smaller. 50/34 with an 11-28 gives a low enough gear for many riders to climb big mountains.

If you need a lower gear for lack of fitness, or touring carrying loads, you can go to an 11-34 in the back and still use standard road derailleurs, keep spacing reasonable, and have a one to one low gear.

If you need an ultra low gear, you can go to an 11-40. That setup has a lower low, and as high,high as a standard triple setup. The spacing is not terrible with an 11 speed cassette, and I'd wager shifts as well or better than most triples.

The applications where a triple is the best answer are getting pretty small in number, mostly just loaded alpine touring.