And in a more general sense, how do you see this trend having changed over the years, both in the D&D community at large and within your own experience? Do people homebrew less?
I think I like the phrase, "implied micro setting". I've been seeing a lot of this lately.
I'm playing in three different D&D games right now. The games skew older - none are run by people who began with 5e. All are run by people with spouses and families. I think this matters * a lot*.
One is running Rime of the Frostmaiden. I expect us to stay within that micro-setting, and not really reference the wider world - we are working to deal with this one problem, the rest of the world is known to exist, but we are unlikely to reference it.
Another has basically set up an excuse for site-based adventuring, dungeon-crawley stuff.. We are a bunch collected by a local sheriff, who offers up some missions we can choose from, and we go and deal with the problem. The current thing for us is a randomly generated dungeon that has reason to be filled with typical dungeon nonsense. I don't expect the world, on the whole, to matter much.
The third started us on Dragon of Ice Fire Peak from the Starter set, and has extended that with some bits he's found (I think on DM's Guild) to extend the run a little bit. We started in Phandalin, and I don't believe we've ventured much more than 50 miles from there yet. Neverwinter, to us, is a distant political entity that wants stability in the region, but otherwise we ignore.
I think the "micro-setting" is dominant here, for reasons to time. These folks have jobs, spouses, and families. Full on worldbuilding takes work, and time commitment. Micro-settings are limiting, but manageable.