On the other hand, a local TV station only needs to know and comply with the election laws of their own city. Google needs to know and comply with the local laws of every city in the world.
If you need an example (which you should not) I worked for a small (~100 employee) phone company and we complied with all tax laws nationwide at a federal, state, county and municipality level. That’s a lot of regulation. It was a lot of work. We did it. What’s Google’s excuse?
It looks to me like Google knew what they were doing, knew what the penalties could be and decided it was worth it.
And it isn't some odd law that the company would easily forget about - FB and Google both get their revenue from advertising, and political advertising disclosure laws are pretty common. While Washington might have some stricter rules, I'd expect the companies to have a division working on compliance.