i guess you’ve never been to BOM (or any other Indian airport, for that matter). You get checks multiple times, and multiple stamps on everything. Security stamps not just the BP, but also the tag they make you put on each carryon to verify it was checked. The stamps on carry on tags are checked as you board by yet more security personal. Inbound on international, they stamp your passport when you clear immigration, then have someone like 20 feet (if that) from the booths looking for the current entry stamp (usually not easily found since it’s not typically done anywhere near methodically - it’s typicaly either on a random empty page not even close to the most recently used page, or stamped halfway over other stamps).

Ive never had close to as many checks in airports in any other countries. It’s been a couple of years since I’ve been through SIN, which yes, still requires paper BPs (at least did until a couple of years ago), but SIN is still easy/efficient to get through, and doesn’t require many checks (even though I dislike security at each gate, but that’s another topic).