I’ve been on Reddit for 15 years and haven’t really noticed any shift for the most part.

That simply isn’t possible. Reddit changed dramatically since the Digg V4 exodus. The site itself has been constantly updated and redesigned / re-engineered adding and removing tons of functionality at least three times. The politics have literally swung all over the place from “tech-bro libertarian” to “conservative” to “progressive”. Content has changed radically in both scope and focus (AMAs are out while corporate run subreddits are in) and leadership has been all over the place.