What do you think is the worst thing about photoshop?

yes, the worst thing is it's not free.

The cost.

Firstly, I agree that the monthly subscription is probably the biggest annoyance. Like others have noted, you used to buy it and own it and you could live without the latest version for a few years until you had to buy it again. But, as for a usable aspect of Photoshop, I find that many of the cheaper programs have so many little quick scripts built in that make things so much easier. You can do almost anything in PS but not as quick in some aspects as other simpler programs. For instance to remove the background from an object in Photoshop can take a few steps (It's gotten easier over the years) but in some programs, it just takes a couple of clicks... even on my phone it's easier to add special effects and quick editing. I wish they would add many of the quick ways to do some more common complicated effects that others have. That's my biggest gripe.

The price and how complicated it is to master.

I've used it since 1997. I joined NAPP (National Association of Photoshop Professionals). I embraced digital and went to yearly David Cross $99 workshops in Charlotte. What I dislike the most, is ONE MORE MONTHLY PAYMENT. I mean you used to own your stuff, but if I stop, I lose all my work. Nothing will open. I don't have a steady income, but I have a great deal of my time invested in this software and it allows me to build the online school because I know how to crop, sharpen, and do all sorts of things you just have to do for social media sizing requirements.