There's a German forum where they've been crowdsourcing this info for a few years[0]. According to their spreadsheet[1] there's a few systems with 12th gen Intel cpus with <15W system power, and it looks like those are using bigger psus so they might be able to be lowered still with something like a Pico PSU. There are lots of low power LGA 1151 setups so as you say things may be getting worse (or the contributors aren't using new computers yet). I think newer pcie generations have higher power consumption, but I don't know if that's true when you put in a lower generation device into a pcie 5 motherboard for example, or if it affects idle power or just peak. It would be nice if this info were more readily available.

[0] https://www.hardwareluxx.de/community/threads/die-sparsamste...

[1] https://docs.google.com/spreadsheets/d/1LHvT2fRp7I6Hf18LcSzs...