I've called for password resets before. Sometimes the email doesn't come in or can take like an hour (fuck "Magic links" and email OTPs...). I've even had support reset it and a day later get the half dozen reset requests I made.
Just because something appears simple and obvious doesn't mean it is. There's a lot of ways for those systems to fail. Might be the user's connection or might be the server the user is connecting to and the customer support is sending through a different one.
Big lesson I've learned is that if a lot of people are struggling with something that seems obvious then it probably isn't.
I just remembered my password reset battle with an online store. Yes, the email or the SMS took too long to arrive and when the code came, it was already expired. And I knew the password, by the way; it was just a "new browser" and they wanted a second authentication. Marvelous.