Thanks for all the replies!
Why Mullvad is different can be found here:
My only question is can I use a password manager extension with mullvad browser and import my bookmarks? Also, can I use uBO hard mode with mullvad or does that worsen the fingerprinting issue?
Also, @imls, what does that website do? It’s a little gibberish for me… 
Thanks!
Edit :
After further analysis, using Mullvad makes absolutely no sense to me. There is no one using it:
Google Chrome: 65.12%
Safari: 18.17%
Microsoft Edge: 5.21%
Firefox: 2.82%
Samsung Internet: 2.66%
Opera: 2.54%
UC Browser: 1.48%
Others: 0.73%
https://www.similarweb.com/browsers/
Not only that, but you have to have people be on the same VPN connections for that pool of unique users to work countering fingerprinting.
Recommending more browsers while Firefox’s market share is plummeting makes no sense to me. I would understand if Firefox was king or had at least 10-15% market share, but this is not the case.
The argument is really valid here: Revise statements on Gecko browsers (Android) to make security shortcomings clear - #54 by ddsn
Also, 2.84% of FF users is still more then 150 million users which would work more be in a similar pool as other users for fingerprinting.
I feel like using FF + arkenfox would be better in that context no?
Am I missing something?