PF is also from 2001. But its roots go further back, I once used a very PF-like syntax on a Unix firewall from 1997. I forget which type of Unix it was, maybe Solaris.
Either way, I don't think there is any defense for the strange syntax of IPtables, the chains, the tables. And that's coming from a person who transitioned fully from BSD to Linux 15 years ago, and has designed commercial solutions using IPtables and ipset.
Alternatively you can use nftables which has only been around for the past 12 years.
I realise that one change per quarter century is possibly a little fast paced for BSD but I can cope with it.