I'd hardly call explaining the network effect and collective action problem fascist apologia, but you do you.
All I'm saying is you can't expect someone to leave behind most of their audience's primary way of communicating with them scot-free. There are always consequences.
Let's say they stop posting on Instagram. Out of those 2.7 million followers, only a fraction will find them on another platform, and thus they simply lose their ability to message to all the people they left behind. That hurts them.
You can still think it's a net good for society for them to leave, or that it would meaningfully hurt Facebook (it wouldn't unless most people also left, but again, collective action problem), but you can't act like they don't face consequences by doing it. It's not "fascist bootlicker apologia" to say that leaving some of your audience behind on a platform reduces your audience.