As a really, really old Undertale fan who contributed to the Kickstarter, watched the development of the game from the demo and aggressively proselyted about it to everyone who would listen (and I was completely right about how it would change the indie game landscape), I miss what Toby Fox was like before Undertale's success.
There was this period pre- and a tiny bit post-Undertale release where Mister Fox was really chatty on all his socials, talked to fans and made stupid posts. When UT blew up, he obviously felt like he couldn't have that casual presence anymore and pulled it all back (also quietly went back and deleted a bunch of old posts).
I miss this sort of stuff.