Unless you spin up an entire devops team plus an ML team to run inference at scale in-house, you're just changing where you funnel your subscription money.

Also: No home-grown CRM will have, in the long run, uptimes anywhere approaching e.g. Office365. You're just smearing one large outage into a lot more small ones, plus a few data losses.

That rent buys you something. The internal development buys you something very different. You might want to make a reasoned call on what you're buying instead of making GDP predictions.