Btree isn't a very useful index type for a vector, though. GIN, GIST, and the handful of new extensions optimizing for vector search are what you'd want (and don't have this limitation).

Aside, you can increase the size of tuples you can index in a postgresql btree by increasing the postgresql page size (requires a recompile and creating a new database instance).

Agreed to the first, but you have to first know that those exist (and what they’re good for). This leads into my second point: IME, the Venn diagram for “people making AI stuff” and “people capable of compiling and running their own DB in a reliable manner” has no overlap.