It's kind of difficult to play well and is full of transpositional opportunities that mean you'll have to become familiar with other openings too.
I think difficulty is all relative. I can say the same thing with Ruy Lopez and Dragon. But I agree with there are numerous transpositions and that's why I like it. You can confuse your opponent with these transpositions (Of course it's double edge).
Most amateurs play e4 and d4 and often are scratching their heads when they face a c4 player. I think that's one of the pros of c4. Kinda funny to see them squirm because they are put into an unfamiliar territory.
Maybe Fischer, Kasparov and Karpov would've been better players if they took a note out of the book of zeitmate. They were just too comfortable in their inferior e4 d4 monkey ways.
Hey, Botvinnik certainly did, with huge success too. Listen to the 2000 you patzer 😛
Rating has nothing to do with this.. just because you are below 2000 doesn't make your opinion worthless.