I don't think the main issue is the end-user software. It's all the other stuff that makes the company work. I work for a small startup, and I can list at least a dozen software platforms that we use, and I'm sure there are dozens more; none of which we could trivially migrate away from. (Fortunately, most of which I don't really want to, as they work fairly well.)
Besides the technical stuff, there's the HR benefits, the expense reporting, the door lock manager, the office reservation system, etc. I'm sure all of these are subscriptions. Many are probably quite inexpensive, but some aren't.
At some point, it will be cheaper to tell Claude, "We use the OverPriced platform. Examine our usage of it, and develop a replacement platform tailored to our needs, and include a transition plan to suck all our existing data and configurations over to the new system." But then there's one more system to support locally, which may not be worth the cost. Or if OverPriced is too ridiculous, do the same, but spin it off as FairPriced and compete.