I try to avoid tumblr if possible and I'm not that familiar with "tumblr culture", but they seem to me the opposite of "nostalgiatards"? Yeah, those people "everything used to be better" still are active on this site, but it's quite small community in comparision to "EVERYTHING IS THE BEST NOW, YOU ARE BLINDED BY NOSTALGIA IF YOU DARE LIKE SOMETHING OLDER THAT FROM 10 YEARS AGO", "today cartoons are the best ever cause Steven Universe and Nostalgia Critic said so" teenagers?
Nostalgiatards was more popular some years ago, now newfags becoming a bit more vocal. Two sides of the same coin.
tbh, I don't think today is the "supah best time to be alive". Yes, some things are really wonderful (medicine & technology helping disabled people), but there are also downsides like western society is often really a mess and everything change so fast people heve troubles to understand world around us. But I don't think 90s or 70s or XIX century or any different times were any better. But not really that worse like some people like to pretend, every era have its pros and cons. Some problems disappear, new are born.