https://cloud.gov/docs/overview/what-is-cloudgov/ is the key page. Seems like they want to have a centralized place where they do the PaaS work across the govt. Let’s see if this ends up being more or less cost effective than what contractors deploy to GovCloud today.
i'll bet 99% it's amazon grift. nothing good comes out of the current regime. Even if you say it started under biden.
In this case (and the same in Australia, UK, Canada) it will be cost of procurement. Ie individual departments have to negotiate (and maintain) a contract. Providing a generic platform (Cloud Foundry, k8s, whatever) on top means that small products from individual entities can get built/deployed without each project having to do a tender to negotiate Heroku or similar.
Likewise, getting a .gov (or .gov.uk or .gov.au, etc) is a big hassle, and with a PaaS you can make the experience a lot better (not in use any more but you can see what it looked like: https://github.com/cloud-gov/cf-domain-broker)
Ie the goal is to reduce the time/steps/approvals required to get a gov website up and running, and cloud.gov in this current incarnation was started under the Obama admin.