Because this thread is about buying a simple B&W laser printer for its reliability, and how that removes the option of printing photos (which is something people sometimes try to do at home), but retains the option to print pretty much anything else[1] people try to print at home.
And then, as a tangent, this is a subthread about using printing services to substitute for the rare — and as you say, declining! — use-case of printing photos, which, when you realize that that's possible, makes the calculus of "buying a simple B&W laser printer for its reliability" much more clear.
[1] (It also removes the option to print e.g. color flyers or posters or business cards, but people don't generally try to do any of those at home anyway, instead deferring to a commercial printer to 1. get a high-quality result, and 2. not have to buy dozens of ink cartridges and spend hours fighting their printer to get a thousand flyers out of it.)
Why do you assume that’s the /only/ thing someone would want printed? Quite odd, considering the declining popularity of print photos.