Here is the current list of extensions I have in my Firefox desktop nightly profile :

Firefox Multi-Account Containers

This let's me use Containers , in a smoother fashion, if forces some domains to be opened in type of container. For instance Facebook is forced to my shopping container (and that's the only thing going into that container).

Grammalecte && Grammarly for Firefox

because I'm so bad at spelling and grammar. These free tools help me with both french and English. I'd use druide's Antidote if I wasn't so cheap.

HTTPS everywhere

Less needed than a few years ago, it helps me secure my web exploration.

Mastodon Share

Because I use Mastodon as my preferred social network and that Mastodon button are not always present on websites. I hope that with the demise of G+, g+ share buttons will be replace with mastodon ones.

Pinboard

Because I liked sharing and saving my bookmarks (delicio.us was a very nice social experience).

Security Report Card

Cause I like to make the web more secure and , I can easily spot the rating when visiting a site. This let's me quickly decide that I will contact the site owner of not and let him know that his site could be configured better.

Universal Amazon Killer

So I don't have to search too much and can use amazon as a search engine and then shop locally

Wayback machine

so I don't stumble too much on 404 :)

First Party Isolation

because I was too lazy to flip a preference.

https://www.hirlimann.net/Ludovic/carnet/?post/2018/12/21/December-2018-what-extensions-do-I-use-in-Firefox-dsktop