YIMBYs are on the forefront of attacking Proposition 13 in California, and YIMBYs are also driving a resurgence of Georgism to use land value taxes to address fundamental inequity.
YIMBYs also regularly support work on non-regulatory barriers, such as the rent increase caps in California (ABA1482), and have even supported social housing bills in California.
There are two types of discussions about YIMBYs: 1) that by far-leftists that see the battle as ideological and about regulation/deregulation and trickle-down housing vs. revolution, and 2) the actual YIMBY activism on the ground which is all about more housing and making housing less of a financial and emotional burden for renters.
Plenty of tax breaks though.