The Jolla C and Aquafish, which are reasonably recent devices, still allow that though. But the real trouble is to find replacement batteries, and Jolla is arguably a bit underground anyway so the question is different with them. I believe Fairphone 2 allows that too, but it's the same, it's a niche product which made a point (a selling point) in being easily serviceable, which is possible only because the vast majority of other manufacturers do not make that choice.