In a world with more and more ways to experience pleasure - hedonism seems like an appealing philosophy to some, through valuing pleasure and minimizing pain, however the main flaw with hedonism in my opinion is it's reductionist nature - it ignores all other values (such as freedom) but pleasure. That doesn't even consider the nature of hedonism (assuming things can be limited to value in terms of one thing - pleasure), with hypotheticals like the pleasure machine which is a thought experiment where a machine that gives you pleasure for however long your life would be consistently, and the idea being not many people would want this, however an hedonist argument may be that this comes from people not actually being able to comprehend what being in a pleasure machine would be like. Another argument against hedonism that might be made against the idea of different pleasures which has been brought up by hedonists is that it may be seen as artificial what someone defines as a higher pleasure vs a lower pleasure. Not only that, but another argument against hedonism is pleasure by itself gained from an action is something that's hard to measure. All in all, hedonism is an interesting ethical philosophy, but I don't know if I could personally follow the goal of maximizing pleasure throughout my life as the only value.
PSA: not a philosopher, may not have represented hedonism accurately etc etc.