just my thoughts
I've always looked at pyro as a more mobile version of the heavy, but with less health
the pyro itself is generally underpowered and the flare gun and degreaser are a huge band-aid for that as people have said
the class in itself isn't very difficult and doesn't take that much practice to be amazing at the class
honestly the best thing about the class is the ability to block movement, but it is really annoying about it because it's not a passive movement blocker like stickies, with which you just think to yourself, " oh I can't pass there, I will die because stickies " but rather it is an active movement blocker, where you have to shoot it to kill it, but it can reflect the pocket's ( in 6s at least) primary form of attack, which is to say, annoying
which is why people hate it
reflects, not puff n sting