Earlier quoted context omitted.
Isn’t Ampere essentially the only company making server grade ARM chips. And all the rest of ARM customers are making mobile/desktop. So Ampere is going after a completely different segment that the rest of ARM customers aren’t addressing.
They're the only company selling server grade ARM chips but others are rolling their own for internal use, such as Amazons Graviton line. That's Ampere's problem really, their biggest potential customers are so big that they can afford to cut out middlemen like Ampere.
Often times these companies might have an idea for how to save power / tweak cores in a weird way on a CPU, but have a chicken-and-egg problem with not knowing exactly how much it'll reduce COGS. Not knowing that and having to negotiate with a vendor (who will often want to charge more for the feature) means that it's difficult to do unless it's an obvious slam-dunk.
By bringing chip development in-house, adding new features skews more towards a political decision that requires less rigorous financial calculations (e.g. "how much power will this save relative to the vendor_cost++ and our own developer cost?" for 3rd-party chips). It basically allows these cloud providers to ship new features more quickly in their CPUs.