If you search the forums, a common use case such as mine is where for some ISP's you need to present a second mac address to get a second public IP. Hence the usefulness of macvlan. There are other uses still too that are relevant. It's also worth noting that the other router OS's out there generally support it.Who in their right mind uses macvlan in 2023?
I'm still not sure the use cases...just read and saw in winbox/cli:tried using the CLI yet?
/interface/macvlan/add <tab> arp comment disabled loop-protect-disable-time mac-address name arp-timeout copy-from loop-protect loop-protect-send-interval mode parent