Driveway and sidewalk cracking issue

Noticed Sunday while cleaning up that several large chunks of concrete at my joints are breaking off. When I say large, I mean ranging from 4”-6” long, and 2-3” wide.

Nothing has changed as far as vehicular use. Slab was poured 5” thick to account for a boat and RV by previous owner. Was constructed about 20 years ago.

Is this just due to settling and wear and tear? What’s a decent fix? I’ve seen some stuff online that is a slurry you can pour to fill and seal cracks, but didn’t see much on its reliability.

Anyone have issues like this lately?