They simply don't have the clout to push around enormous American companies. It's a tiny country. If the EU or US were proposing such a law, you should take it seriously, but this is just a joke.
It's very transparent but also standard operating procedure for the current UK government.
> If the EU or US were proposing such a law, you should take it seriously
Judging from a few quick searches, there are more Facebook employees in the UK than in Ireland which is their main base of EU operations. They also have a presence in Switzerland (also not EU). FB apparently have some employees in Germany to comply with local hate speech laws, do marketing and HR work, but it doesn't seem like anything they'd miss much if they had to exit especially as they're laying people off anyway.
Now that said, I think Meta can win against the UK govt if they want to duke it out but the idea that the UK is a "tiny country" vs the EU is not reflective of Meta's actual exposure. The EU is not a particularly attractive place for tech firms to hire.
Regardless of employee count in the UK office, it's only 2% of the market. I have no doubt about the choice I'd make if were faced with the same choice: especially since companies already have plans to decrease headcount.
They would drop the UK in a heartbeat.
They also know this happening would topple the government in the UK.
So it will never occur if they threaten it.
Let's not get carried away. There are other apps with equal parity. Most people in SE Asia use Line perfectly well. There's also Signal and Telegram