Kkmou
Just for you to known, they store the compose file. It's in their compose folder on the data volume.
They will don't care, not their money, not their job. Can't blame them
You will never find a tool to manage everything. It's better to understand the pro and cons of each. The ability to use a real programming language is really the game changer of these new IaC tools (cdk / pulumi). You get a lot more momentum to involve others (devs) and share knowledges. If you don't find value in that, you have no reason to switch, you will lose the terraform massive ecosystem.
For me, it give me the real opportunity to progress on my coding skills in association with my ops/infra routine. It's a lot more fun than any hcl.
It's not mandatory to use pulumi cloud, you can selfhost, or use any object storage backend.
In AWS, you can use Aurora to scale reads access over multiple instances. It's easy to setup and you can use scaling policies to follow your load. You need to check your billing, it's not the cheapest service.
Don't think git as a sync storage, more like to merge works.
If you need to share files between computers use a shared storage.
Always use the right tool for the job. Mount a shared storage or use synctools rsync, etc