That Firefox logo was simplified, but not oversimplified. Even with a very small icon size you can still tell it’s a fox that is (on?) fire. The Firefox Family logo is oversimplified, just being a swoosh, basically.
I used to not like the new Firefox logo when it first came out, but by now, I couldn’t do with the old one, it looks so much… And I bet if they changed it back, it would take me 2 months max to switch opinions right back.
At some point I have to accept, I’m just an ape of habit.
Honestly, its considered a hot-take but I do like minimalistic logos cause they are easier to recognize. Also they tend to better fit with the rest of the UI and products.
The new reddit logo is pretty awful but both Firefox logos are fine IMO. They are both pretty well done, just in different styles.