> Safari already implements Manifest V3 (it never had anything else to block ads)

This isn't entirely accurate. Confusion on the issue abounds.

From 2010 to 2019, the safariextz format had support for webRequest BlockingResponse https://developer.mozilla.org/en-US/docs/Mozilla/Add-ons/Web... and indeed there was a Safari version of uBlock Origin. This was eliminated in Safari version 13.

The "newer" (2015) Safari content blocker API is similar to Chrome's declarativeNetRequest. However, Manifest V3 is far broader than just eliminating webRequest BlockingResponse, though that's what people tend to focus on. For example, there are strict limits on script execution that also cause problems for userscript extensions.

Safari web extensions (2020) will continue to support Manifest V2, albeit without webRequest BlockingResponse, which Safari web extensions never supported. Apple is in the process of adding MV3 support to Safari web extensions without deprecating MV2 (just like Firefox).

In a sense, Manifest V3 and delcarativeNetRequest are separate issues. After all, delcarativeNetRequest is also supported in Chrome MV2. Chrome took the "opportunity" to eliminate webRequest BlockingResponse in MV3. Safari took the opportunity to eliminate BlockingResponse much earlier. But MV3 could have supported BlockingResponse if Google had wanted; there's nothing inherent to MV3 that precludes the API, other than an arbitrary decision.

It also doesn't support AV1 or AVIF.

A cynical part of me thinks Safari supported JPEG-XL for pure tribal warfare, as its the "anti" AVIF. That would be so petty...

Safari already supports AVIF.

Actually Safari added support for three new image formats at the same time: JPEG XL, AVIF and HEIC.

> (it never had anything else to block ads)

I've used Wipr for a long time on both my Mac and iPhone, this isn't true.

Wipr says it uses Safari's Content Blocking API, which has restrictions similar to those found in MV3. I think this is what GP was referring to, since it means Wipr/MV3 is limited in what they can block compared to, say, UBO on Firefox.

I think the big issue with MV3 is the limit of like 30k content blocking rules per extension, whereas Safari's is unlimited(?)

> Safari's is unlimited(?)

Safari content blocker rules are limited. Formerly 50k, increased to 150k: https://adguard.com/en/blog/adguard-for-safari-1-11.html

Right, but that article mentions the workaround. Wipr gets you to enable a few "extensions" (Wipr Extra, and Wipr Parts 1-3) when you set it up. Each one grants an additional 150k rules