As a game studio - a developer rather than a publisher - it’s very much hand to mouth. You are paid by the publishers on delivery of milestones. Milestone reviews can sometimes be subjective. You’re basically the lowest link in the food chain and can be subject to a publisher’s whim, which can often be a bit random depending on your external producer. Keeping such a studio open in the long term is about chasing new contacts, and any gaps between contacts is expensive because you aren’t generating any income, but are having to pay wages. One or two project cancellations can easily shutter an independent developer.
In some cases studio owners may simply want out, or they might legitimately see a sale as bringing stability to the studio… Or it might just be greed. But I think it’s hard to say whether a studio would have a safer long term future being independent or being sold.