I'm afraid I don't buy this unfounded muck-slinging.
I know the open-source evangelists live in a rose tinted world where open-source automatically equals better.
However I think its only fair and reasonable to admit that it is possible to make high quality closed-source software.
Specifically, in terms of Adobe, I think it is deeply unfair and unfounded to call it "inferior". There is, for example, high-levels of integration between Adobe tools that is simply not present in open-source.
Ultimately money talks. December 2021 there were 26 million Adobe Creative Suite subscribers and growing. If Adobe was that shit, do you really think people would continue paying them ?
I know some people running companies in the design sector (larger companies, not one-man band freelancers), Adobe is a necessary business expense, they pay it because they want it, because time is money, and if their designers get the job done better, quicker and more efficiently in Adobe then they will pay the subscription. (Oh, and to address your specific point, the designers spend exactly zero hours watching training and tutorials on the Adobe website).