I have no idea what Verizon's plan was, but I assume Apollo's plan is to ride Yahoo into the ground, and they've forecast the present value of the revenue vs costs, and it works out.

I left Yahoo in 2011, but back then, profit margins were usually OK but not nearly as good as competitors. Mostly properties were run by small teams but competing ok against much larger dedicated companies. And then there was search; outsourcing it mostly to Bing but keeping a large team and crawling infrastructure to do customizations didn't make sense to me, but it's what happened.

I don't know how much of the small team enabled by corporate stuff + central advertising team still works at Yahoo, if it's still there, maybe there's hope.