I would like to weigh in on this with my observations. Prefaced that everyone's experience is a little different and we don't yet know the entirety of values tweaked in A21.
I play solo, but I also play with 2 of my friends. When I play with my dudes, the typical day, especially in the first couple days, 2 of us run around and the other stays out and chops wood. He farms straight until an hour or two from dark, then begins building, from scratch. Where he was a little behind the first night, he's far ahead of us by morning. Soon he makes cobble stone his mission.
What I'm getting at is this. In terms of raw experience gain- undertaking a building project is the fastest way to get there. Personally, I believe it could use a 5-10%(?) nerf due to how eschew it is in terms of time invested to XP ratio, even if you have to spend large chunks of that time obtaining resources. - But that might really make the "They're going to ruin building! There's absolute no reason to build any more, EVER" crowd think they're being targeted.
... C'mon guys, you know you're digging/chopping XP to plaster it to your walls, right? Is that not reason enough