I think it's polarizing, just like Seinfeld and other generational TV shows, for reasons that are very intrinsic to the sitcom genre.

First, every sitcom is an acquired taste. Because its humor is based on saturation (with tropes, characters, situations), you have to let it percolate a bit before it starts hitting. It is extremely rare for a show like that to be funny right from the start of episode 1 (even when they frontload a lot of the humor in the pilot to sell the pitch). It's a known issue when you're writing fiction of any kind : if you want to hit deep, you need to take some time to expose your characters, motivations, situations etc... But you run the risk of losing the reader before the payoff. If you skip that and hit early, then your payoffs will be more vague and shallow because they're not backed by a solid foundation. It's a balancing act, but with this genre in particular, which can get to large season counts, you have to have at least a bit of expo.

Traditionally you often hear that you need 1 season to get into a sitcom (also because that's a reasonable timeframe for the writers to hit their stride), but a lot of people aren't ready to sink that kind of time into a show they're not certain about so they'll watch a couple episodes, miss the entirety of the whole point of it, and ditch it.

Secondly, Friends in particular is in a sub-genre of sitcom : the "group of young people having mundane adventures in the big city". The appeal of that sub-genre is kind of like a para-social relationship, where over time it feels like those people are part of your friends group and that makes everything deeper, more significant, and funnier. Obviously this only works if you are tightly packed with the characters group, in terms of age, culture, life experiences etc...

When somebody under 30 watches Friends they'll feel that gap and, unless they develop a personal affinity to the setting, it will all fall flat. On average each given generation cringes at the previous generation's foundational sitcom.