few days ago I had ipv6 enabled on my pi4 and was trying to update it, turns out that the ipv6 address of archive.raspberrypi.org was returning 404 (its fixed now)
but it took me like 3 seconds to just net.ipv6.conf.all.disable_ipv6 = 1, and i am not gonna enable it until something on ipv4 does not work
(and by ipv6 i mean native ipv6 from my ISP)
it has been like that for the last 15 years, since we gave native ipv6 to our users in my ISP, people just had worse experience than not having it.