Page Keyboard Navigation on MacOS
Ok, so I feel like a complete idiot right now.
When I've been trying(and failing) to use the tab key on my computer(it's a Macbook) for what feels like forever now. Turns out, it was as simple as hitting control + fn + <<(<< is F7).
To be honest, I thought that it was just an issue with FireFox, and then I read Browser keyboard navigation in macOS and realized that it was an issue with MacOS! This should really be an option enabled by default, but Apple is stupid.