Those are "old" tools. I bought one almost 40 years ago and used if often enough. That one was one-piece, ratcheting, just for slotted screws When you need it, you're glad you have it. I don't have any now, including the ones I linked to. Haven't missed them, but I hardly do anything any more. Most stuff is engineered now to not require an offset screwdriver on a fastener.
"Special" tools are kind of always in there own category in those terms. But I hear you about the thickness. Those multi-bit offsets wouldn't get on some of the screws I used my old one on. It could get into a space half the height the new ones can. Something like the offsets here, but a little thicker.