It's likely that ARM will find a place in a cloud. But, at, least at first, it will be in some specific parts of a cloud offering.
I don't see ARM displacing X86 on VMs offering like EC2 any time soon, an ARM offering will exists (and it already exists in fact), but it will remain a small portion.
However, some parts of a cloud offering are completely abstracted from the hardware: DNS, object stores, Load Balancers, queues, CDNs... for these, from the point of view of a developer, CPU architecture doesn't matter at all and if the cloud provider find it more interesting to use ARM (maybe with some custom extensions), it will probably switch to them.
From there, it can gradually go to services where architecture kind of matters, but not necessarily, like serverless, or Postgres/MySQL as a service.
And while it grows, ARM CPUs will improve for other use cases, and maybe overtake X86 VMs.
The other possibility is a massive cost reduction like 3 to 4 times cheaper for equal performances, but it's not really the case right now.
Also, given the all the wasted money I've seen on AWS ("app is leaking memory? just use a 64GB instance"), I'm not sure it's a good enough incentive. However we are specialist at being penny wise and pound foolish.
I don't see ARM displacing X86 on VMs offering like EC2 any time soon, an ARM offering will exists (and it already exists in fact), but it will remain a small portion.
However, some parts of a cloud offering are completely abstracted from the hardware: DNS, object stores, Load Balancers, queues, CDNs... for these, from the point of view of a developer, CPU architecture doesn't matter at all and if the cloud provider find it more interesting to use ARM (maybe with some custom extensions), it will probably switch to them.
From there, it can gradually go to services where architecture kind of matters, but not necessarily, like serverless, or Postgres/MySQL as a service.
And while it grows, ARM CPUs will improve for other use cases, and maybe overtake X86 VMs.
The other possibility is a massive cost reduction like 3 to 4 times cheaper for equal performances, but it's not really the case right now. Also, given the all the wasted money I've seen on AWS ("app is leaking memory? just use a 64GB instance"), I'm not sure it's a good enough incentive. However we are specialist at being penny wise and pound foolish.