In the past (years ago when there was a working x32 Debian installer briefly available) I have actually used x32 on some devices with 64-bit CPU but limited RAM, like PC Engines APU series boards. Nice low power boards (fully open firmware, coreboot instead of the proprietary BIOS, serial console, no power wasted for the unused graphics) but 4 GiB of RAM chips (even with ECC!) soldered permanently, no way to replace the DIMM with a larger one. Good for uses such as routers, or GPS-synced NTP servers (including precise timestamping with a little hardware hack to connect 1PPS to one of the i210AT NIC pins). I've seen quite significant memory savings when running BGP with full Internet routing tables.

RAM is getting more expensive again (thanks to AI) so it might make sense to reconsider the x32 ABI for such embedded, industrial, non-desktop uses. Also good for real VMs, using more RAM on the shared host but more secure (better separated) than containers affected by the recently found local privilege escalation vulnerabilities.