It's free (not sure if FOSS), and there are non-essential-but-nice-to-have features that are paid, just to support the dev - but the free features are awesome, and more than enough for me.
You have absolutely no idea what a gem of a comment you wrote ! This clears up a lot of things for me. Thanks !
I also read that the original Invidious Dev (Omar Roth) has shut down his instance in 2020, and is also taking a break from active development. Other Invidious instances might still be around, but for now it's not the most interesting thing to check out, at least for me.
I use MiXPlorer.
It's free (not sure if FOSS), and there are non-essential-but-nice-to-have features that are paid, just to support the dev - but the free features are awesome, and more than enough for me.