Totally right, perforce is used by almost all large game studios. But it's painful to use for smaller studios and indie devs - it requires managing your own server with configuration, backups, networking etc. It's also not great for cloud based workflows and remote work, and super expensive with rigid licensing.
Most of the time we need to host our own servers for licensing issues, you might need to consider a "on premises" option if you want to be an viable option for a lot of studios.
This sounds like a classic innovator's dilemma style division in the market.
The incumbents need to cater to existing customers with a need to host their own servers for licensing reasons; but this forbids them from using cloud native features in the core of their products.
There may well be space for a newcomer to make a cloud only product targeted at the subset of studios that have the legal ability to use the cloud. Instinctively, there may be some useful features around large files which are possible in the cloud but impractical in an on prem environment.
My understanding from reading much of OPs responses is that “the cloud” may be vendor locked to AWS. There are serious issues there to hosting your code on servers most likely owned by a competitor. E-Commerce, video streaming, games, AI, video production, electronics, retail, pharmaceuticals, logistics, publishing, etc. Like they literally picked the worst vendor to build this on.
Why the worst? Microsoft is a more serious competitor to game studios with Xbox Game Studios and now Activision Blizzard. (And yet they do use Azure).
You definitely have a point reg vendor lock, we've planned for this and Diversion will be able to run in any cloud and on-prem in the future (we are running it in containers now).