They haven't released a report in years but people's preference has been for shorter time controls more and more over time since. Many streamers have commented on the change so it would be curious to see. If most people truly like longer time controls classical will be an actual category on this website. But it would be silly for them to add that since almost no one would play it even if it was considered 20 minutes. Lmao. I come from liches and I could tell you most classical players are literally provisional accounts at my level. this is online chess. Blitz and bullet are preferred for an endless amount of reasons. And if we are talking title players especially super GMS bullet is the most popular and no I'm not saying that because I like playing it. I don't even like watching it.
I think you are overlooking something here, the reference doesn't include the correspondence/daily format. I once saw statistics that indicated that >25% of the games on chess.com were of the Daily format. This might help explain the unpopularity of classical formats and note that titled players are very unlikely to acknowledge playing the Daily format on their main accounts.
I don't quite understand the huge popularity of the Daily Format - working lives? - but I have seen no reason to doubt the statistic - some people play 100s of Daily moves per day! The Daily format is an aspect of chess.com that gets little or no attention but is a very busy environment.
Note: Using Lichess filters the statistic >25% is not supported - low single digit % - however the Rapid format is far more popular on LiChess than on Chess.com. I suspect this was why chess.com amended it's definition of Rapid some time ago.
Daniel narodinsky . . . now considers 5-minute Blitz classical online
I'm sure those weren't his words.
But sure, 3 minute is the gold standard for online blitz. It's what experienced people play. I haven't played 5 minute blitz in probably 10 years.