I used postgrest (without htmx) on an old project; it's impressive how far you can push it.
HTMX seems like a perfect fit for it too, although I'm not sure how much I really want to maintain htmx templates inside SQL functions...
Zero interest. BTDT (php). Static analysis, local testing, refactors, bulk changes delivered atomically (transactions, if you will) are missing critical features with this type of pattern. Great for hacking around, but not for making something stable.