Playtime has some of Tati's and Mr. Hulot's best sight and sound gags, but why did it have to go on for two-and-a-half hours? No votes.
I think it's understandable to question the films run time in that it doesn't really have any specific narrative or character arcs that need a lot of time to resolve. It also doesn't span generations or eons of time in telling its story. It's just a single day. And because its Tati, is populated mostly by his gently rendered (yet frequently very pointed) observations about modern life. On paper it doesn't feel like it should require much more than 90 minutes, if not less. After all, it's really just a series of gags when you boil it right down to its essence and if the Marx Brothers had ever claimed to have needed two and a half hours to articulate their particular brand of humor, I might be similarly dubious (and I say this as a huge fan of the Marx Brothers).
Personally though, I think the runtime is essential to the films revolutionary nature. I'm generally a person who rarely sees film comedy as being terribly cinematic. While there are certainly exceptions, comedy most often feels like it is just using the medium of film as a convenience to deliver its punchlines to the maximum amount of people, and rarely utilized much of its cinematic potential to push anything further. Playtime though seems to almost approach its use of gag humor as an entire universe for its audience to exist inside of. We are in essence made to sit back and leisurely watch life unfold, while in the distance, Tati might slowly tease out some peculiarity of our existence (and almost never call any attention to itself, his jokes are so organically incorporated into the picture frame they as a result become a intractable part of life itself).
Could the movie have worked at a slim 80 or 90 minutes? Probably, and it would have likely ended up being very similar to what makes M. Hulot's Hollday and Mon Oncle successful. Great movies both of them, each full of some of the greatest comedic poetry, as well as understanding how film can deepen the effect of humor. But neither of them are ever going to quite be Playtime. And this has a lot to do with how much time we are left contemplating this city he built specifically for his production of this film. This extra time no only allows the whimsy of his humour to become all the more grounded in an existence that slowly seems to start mirroring our own in how it slowly unfurls, but there is also a beautiful boldness in the philosophy he is employing by letting his slight, little comedy take up as much cinematic oxygen as something like 2001: A Space Odyssey.
Because of this, when I watch Playtime, I'm not just left with the mirth his approach to comedy brings out in me (and, yes, it is a very funny movie for those willing to let their eyes and senses roam around the screen), but it also feels sadder than the others, because there seems to be a sense of a man staring at each of its scenes of city life as if trying to remember something that was once beautiful there, or hoping if they keep staring long enough it will return. It is one long, lingering gaze at a world slowly being rearranged out of shape, and the feeling that this may be the last time we'll even recognize the humanity that lives inside of it anymore. And this gaze needs its time.