I am assuming their only liability is the one they agree to. They very likely have terms that say no refunds if the company goes bust, changes hands or pivots.

I am assuming their only liability is the one they agree to. They very likely have terms that say no refunds if the company goes bust, changes hands or pivots. On the financial side, it is just the lifetime value of a user upfront. Even in a SaaS, most users will churn and stop using it so it is in the businesses best interest to collect all the money upfront.