I think it's plot driven railroads with set piece combats that people are playing. That seems to be the underlying assumption behind most of the posts on Enworld at least. It's not that they're not doing something that might be able to be called a dungeon crawl in some sense, but it's not the old school kind of exploratory dungeon crawl.
In a way WOTC knew their audience with 4E they just marketed it badly and made it overcomplicated and too unfamiliar.
This is for example one of the issues with rests. People think that 6 combats is too many because that means they have to have six planned encounters to throw at the party that mostly end up being unsatisfactorily easy. It doesn't seem to occur to them that the players might make the decision about whether to engage in a fight (and that if you can take out a group of potential enemies quickly and efficiently as part of pursuing a player driven goal then that's not a boring combat that's a satisfying step forward). It's when "bandits attack" and you spend 30 minutes fighting a boring combat for no purpose that it all falls apart.
I play a lot of 5e official adventures. And there is the range you'd expect.
The most popular adventure book has been Curse of Strahd. It's a genuine sandbox adventure. It has some old school elements. Like you can encounter challenges well beyond your level, and they will not be dumbed down to adjust to your level (unless the DM makes an adjustment on their own). It's a combination of mystery, politics, combat, dungeons, and wilderness exploration.
We've been playing through Tales from the Yawning Portal. Which is a series of older adventures, mostly dungeon crawls. I love it. It's been a total blast.
Most recently I've been playing in Waterdeep: Dragon Heist. I'd say it most closely hews towards the "plot driven railroads with set piece combats" that you mention. It's heavier on role playing, mystery and politics with some set piece combat. There are still some dungeon crawls, and some exploration (city based). But there seem to be a lot of pre-planned encounters which happen at specific points in the adventure. It does give lots of opportunity to choose who your allies and enemies will be, and it does allow variation in who the villain will be. But for me there's been a tad too much railroading. Fortunately my group knows how to go off the rails pretty well, and it's been very fun despite that bothersome aspect to the adventure (we've already very meaningfully altered the course of the entire city in ways not contemplated by the written adventure which has kept our DM on his toes). And it's the precursor to an extensive mega dungeon adventure. We plan to dive into that adventure while still engaging with the city above, which should break through the last of the railroading left in the city and open it up to a more true sandbox.
I've played some of the earlier published adventures from WOTC, and they also had more of a dungeon crawl element than you might expect.
Importantly, if you look at their adventure sales data through Amazon over time, you find the "plot driven railroads with set piece combats" adventures do not sell as well as the more sandbox-oriented ones. So I don't think the claim that the majority of players are focused on those kinds of adventures is particularly accurate. It's much more varied than that.
And if you think about it, that makes sense. The popular streaming games teach players to do their own thing and "tell their own story." While I might not be a fan of those streams, they're not creating players who like to be railroaded. The sandbox remains alive and thriving under 5e.