I find it fun to world build, although I often find a problem of being too lazy to sometimes write it down so I end up forgetting some parts of it.
Although some of it / most are usually ingrained in my brain anyway.
I find it easier to world build alone, or to keep it to myself mostly unless I'm sharing it for an RP or something. Only reason I worldbuild with others is for RP or of course stuff like DnD.
Is great fun.
I use a 'make it up as you go along' approach to my world building. I'm writing an anthology series where each story takes place in a different part of the world with a different group of characters. The idea being that the further I go, the more detailed and integrated my world gets.
I've got a setting I've mucked around with in one form or another since I think 7th grade, maybe 6th or the summer in between them. It's changed a lot in that time, and the time period I focus on has also shifted. Currently I have a Leuchtturm 1917 A5 journal that I intend to collect this information in, as to make it easier to reference and to build further on. Eventually I might move from that system to a ring- or discbound system where I'll be able to insert dividers and move pages around, but I like my hardbound journal for how easy it is to shelve or carry around, while discs or rings would add a bit of awkward bulk. Or I'll just store it all in a locked-down wiki.
I also have an alternate Earth superhero setting (think a slightly more lighthearted X-men, though still with some dark elements, just less srs bsns) that I want to get back into, along with a couple other Earth-analogous/alternate Earth settings including the one for my and husband's webcomic and the one for what is supposed to be a story series (CW: recreational drug use) that I should also get back to and finish.
And then there's a sci-fi/fantasy setting (as in, spacefarers landing on a planet that has magic and other fantasy elements) I'm slowly developing for a work I want to write, another sci-fi setting I share with hubby-dearest centered around the adventures of a mismatched diverse merchant crew of a really shitty spaceship (even their mechanic refers to her as the Bucket o' Bolts), and the fantasy setting my shapeshifter character comes from.
I don't think it's possible to write in any setting that isn't straight regular world, if even that, without doing some degree of worldbuilding.