> refuse to let them export it
Honestly, it's hard to feel too bad for people making the choices to use this stuff without considering an escape plan or safety net and then getting burned by it.
You choose to not get fire insurance on your house, your house burned down... like yeah, that sucks, I do genuinely feel bad that happened to you. But also, you took a risk presumably to save money and it bit you in the ass, and now you unfortunately have to pay the price.
Sometimes SaaS really does make the most sense. Having your people doing part-time, non-core operations of an important service they are not experts in can be a huge distraction (and this is a hard thing for us tech people to admit!).
But you need to go into SaaS thinking about how you'd get out: maybe that's data export, maybe it's solid contracts. If they don't offer this or you can't afford it... well, don't use it. Or take the risk and just pray your house doesn't burn down.