Wasn't it 4% of your worldwide gross revenue? That is much more substantial. But I guess it would still be profitable for FB to pay such a fine every few years in order to be able to continue doing business in the EU.
Yes, it would still be profitable, the only thing I'm not sure about is if the fine would be cumulative for every misuse instance (i.e. in the Cambridge Analytica situation, 50M * 4%WGR) or if, every time a misuse is found, it's a una-tantum fine.
Might also be FUD to force countries in the EU to regulate tax at the same level, but I doubt Ireland/Holland will go down without a fight