Would PostgreSQL adapt to a HYPOTHETICAL hardware that grows and shrinks as load increases?

Hi there,

Let's imagine there is a type of Server(Physical, Unikernel, or Hypervisor,
doesn't matter here) that could allocate more RAM, IO bus, Network
bandwidth, or CPU power through API calls. The increase or decrease would
take a few milliseconds to effectively take place.

This hypothetical VM would receive commands from external monitoring tools
that detect load and complex queries (through statistics and ML) and would
decide to adjust the VM size accordingly,

I have a rough idea how complex (or impossible) it would be for ANY modern
database to rely on an always-changing "hardware". As there are many CORE
datasets in memory and statistics around the hardware, so changing this
every now and then seems to require a completely different strategy.

I am not an expert but as I see more and more Serverless solutions tackling
RDBMS, and PostgreSQL being the leader in the cloud world, I was wondering
if one day PostgreSQL could take advantage of these scalable VMs.

- It seems to me that scaling up could be less complex, as PG wouldn't
have to select what to invalidate from its cache layers and statistics.
- Statistics would be affected every time the size of the instance
changes
- The instance should probably have a minimum size to avoid cold starts.
So scaling to zero wouldn't be possible.
- If the server where the VM/Unikernel is running has no more available
resources to grow, what should be done (maybe this machine should share
resources with SPOT only, so it could forcibly deallocate the spot
instances before increasing the size of the DB VM?)

Any help to educate me on this would be greatly appreciated,

Thanks