Firefox

Most of the "privacy" extensions do little to nothing to protecy your privacy as of today, due to them either being abandoned, replaced by features integrated in ublock origin or just not relevant anymore because of the actual fingerprinting strategies employed at the current time.

And it is not "random uhh acktshually🤓 lemmy user" who's saying this, but the wiki section of the arkenfox user.js project. https://github.com/arkenfox/user.js/wiki/4.1-Extensions

Installing them only expands the attack surface of your browser, consumes resources and makes you more fingerprintable.

They are remnants of a time when you needed a full day and a degree in CS to properly set Firefox for privacy. Luckily, things are more straightforward nowdays.

Temporary containers:

TC is no longer maintained. While TC provides sanitizing, and uses a dFPI-compatible API, this is not why it is recommended as optional [...]

️Sanitizing in-session is a false sense of privacy. They do nothing for IP tracking. Even Tor Browser does not sanitize in-session e.g. when you request a new circuit. A new ID requires both full sanitizing and a new IP. The same applies to Firefox.

uMatrix:

No longer maintained, the last release was Sept 2019 except for a one-off patch to fix a vulnerability Everything uMatrix did can be covered by prefs or other extensions: use uBlock Origin for any content blocking.

ClearURLs:

Redundant with uBlock Origin's removeparam and added lists. Any potential extra coverage provided by additional extensions is going to be minimal

LocalCDN:

Third parties are already partitioned if you use Total Cookie Protection (dFPI)

Replacing some version specific scripts on CDNs with local versions is not a comprehensive solution and is a form of enumerating badness. While it may work with some scripts that are included it doesn’t help with most other third party connections

CDN extensions don't really improve privacy as far as sharing your IP address is concerned and their usage is fingerprintable as this Tor Project developer points out. They are the wrong tool for the job and are not a substitute for a good VPN or Tor Browser. Its worth noting the resources for Decentraleyes are over three years out of date and would not likely be used anyway

Cookie autodelete

Sanitizing in-session is a false sense of privacy. They do nothing for IP tracking. Even Tor Browser does not sanitize in-session e.g. when you request a new circuit. A new ID requires both full sanitizing and a new IP. The same applies to Firefox

Cookie extensions can lack APIs or implementation of them to properly sanitize e.g. at the time of writing: Cookie Auto Delete

As of Firefox 86, strict mode is not supported at this time due to missing APIs to handle the Total Cookie Protection

Consent-o-matic:

No user.js reference here, but I expressed my doubts about it in the comments yesterday https://feddit.it/comment/6471917

Bypass paywalls clean:

While it's amazing, it's also available as a filter list, from the same author

In short, don't bother with more extensions. Just add ublock filters when/if needed, but this is one case where you get 80% of the result with 20% of the effort (FF strict privacy protection mode, ublock origin, switch search engine)

Also, weirdly enough, nobody mentioned the bitwarden extension. Thanks to that (but not only), they manage to provide an amazing password manager service for free, the paid options are cheap, it's full featured, well integrated with the browser, open source and self hostable.