Google has huge annual revenue from EU advertisers and significant assets within EU; the main EU subsidiary "Google Ireland" has something like 50 billion euros annual turnover - of course they have to pay this unless they want to withdraw completely.

The fines were issued to Facebook Ireland and Google Ireland, which are within the jurisdiction of the EU.

Typically if a company wishes to do business with EU residents they have to comply with the EU regulations. Many larger companies choose to incorporate somewhere in the EU to make this easier or in some cases they will even incorporate in each country that they do business in.

Can you elaborate why this is laughable to you?

This might be a shocker, but even American companies have to obey the local law of the country they operate in. Big tech runs offices, has infrastructure and profits of a huge market in those countries. All of this is leverage a country can use to enforce their law.

Google and Facebook are publicly traded companies. Indirectly, I own shares in both. I'm not American, nor are many of their workers, nor are many of their officies, nor is Sundar Pichai. Crucially, these 'customers' are French and, like you and I, if you want to sell things (belonging) to French people in France, you have to follow French laws. Assigning nationalities to companies is bizarre.

Yes, if they want to keep doing business in France.