General Motors used to be, for a time, America’s largest car manufacturer with a peak market share of 50.7% in the US in 1962. In 2016? 17%.
It doesn’t matter whether the Photoshop is still king, because kingdoms usually revolt when the king becomes tyrannical. Even if Adobe’s brand presence is such that it has become a verb, it doesn’t garner loyalty. In fact, if the ubiquitousness of the phrase is so great, it can eventually become a generic word like ‘aspirin.’
Now, yes it is true, Photoshop is the industry standard — but when a majority of your customers aren’t reliant on industry standards as they are sole proprietors, freelancers, and students, standards aren’t important, because cash flow is.
I don’t know if Adobe is paying attention or cares (because they know their business model better than anyone else) but there’s certainly a groundswell of dissatisfied photographers (and others) who are looking for alternatives.