Lots of things will break if you disable ipv4, including my work provided zscaler windows laptop (and not break in the good way where it fails open when you block traffic to zscaler nodes on your router)

Very little will break if you disable ipv6

Enterprise malware not doing v6 properly hardly counts, it’s a good day for them when they don’t just bsod your entire network.

A lot of stuff breaks when you run Zscaler.