But doesn't this content need to be reviewed (read permitted) by other non-anon user accounts?

This is a good and sad point. I was on the wiki page for derivatives and found it was locked due to vandalism. On one hand, we don’t want pages locked because that defeats the point. On the other, how do we stop every troll high schooler who just learned derivatives and messes up the wiki page for lulz? We either need active watchers (surprisingly and fortunately pretty easy, wiki editors are a passionate and eagle-eyed group, but I wonder how long and how much of this is just the initial hard core fans from the early days) or to have some deterrent to vandalism in the first place. For some, maybe this is IP address logging (although as someone else noted in the thread, at what point does this sink anonymity?). For others, maybe creating an account. In practice, neither of these work 100% of the time. I have seen vandals from both IP accounts and registered accounts in about equal frequency.

GP's "directly" is a pretty large overstatement, but at the same time I've noticed something of an uptick over the past couple of years of people saying that IP addresses aren't PII or that people shouldn't be concerned with them getting leaked, and I just don't think that stands up to much scrutiny.

If IP addresses didn't matter for privacy, Tor routing wouldn't exist. If IP addresses weren't useful for blocking specific users, IP bans wouldn't exist. If IP addresses weren't useful for tracking, operators wouldn't have gotten up in arms about Apple's private relay service. Obviously this stuff matters.

Remember that not everyone lives in or around San Francisco. For someone in a suburban/rural area, an IP address combined with things like timestamps, user ids, and the text of the edits can go a really long way towards unmasking them. Even for people who live in more urban areas, it is still obviously easier to find someone who lives in San Francisco than it is to find someone who could be living anywhere on the West Coast. If they could also have been using a VPN, or time-shifting their posts... that makes it even harder.

In contrast, how hard do you really think it would actually be to get some address data from a voter roll or via a warrant or even just through one of the scummy person lookup services online and to iterate through everyone who shares that IP address and check to see how many of them are named Pietri? Or who have shared the username wpietri across another account, or posted somewhere else at roughly the same time? Your IP address is drastically reducing the search-space for other attacks, many of which (timing, text-analysis, etc) are impossible to get rid of when making a Wikipedia edit.

Comcast has a portal for law enforcement to request subscriber information at https://lea.comcast.com . That IPv6 address, plus the current date and time, uniquely identifies you by name and service address. Any edits you make to Wikipedia from that address are not anonymous.

3270 23rd street, 94110?

The person y'all are downvoting is not technically incorrect if they're in the EEA, as this is exactly how GDPR treats it. Because there exists a party that can map it (your ISP), it's PII under that law. Of course this may be different in other jurisdictions.