Getting funding from your biggest rival isn't exactly the most stable strat long term...

Mismanagement of funds/personnel not withstanding.

to be fair it worked for like 2 decades, it feels long termish. but i don't really disagree.

the current model really is: Google needs Mozilla to survive so that they have less chances to get split due to monopoly in the browser market

actually I'm pretty sure that the money goes to the mozilla innovation fund and not directly to mozilla? not sure how easily they can withdraw money from there.