Some of the goods you just can't get anywhere else, and they know it.
Aurora - tidb or vitess or cockroachdb or citus etc etc
Glacier - there is backblaze, also onprem vendors
Sqs - just use Nats
Having said that, and please keep in mind that I do not have an idea much about hardware so this is a guesswork; more of a question than a statement..., I do think that the Graviton price vs performance might not have a direct benefit outside of AWS. It's cool for AWS because they have less stuff to manage at that scale and it might be cheaper for them to buy and iterate because only they use it. It looks great to the clients because the perception is that the value is better. But AWS runs 80 AZs in 25 regions so it benefits them at that scale.
Realistically, even if one had couple of hundreds of racks, does it matter at that scale?
SQS is a message queue service. It's a bit weird to claim that as "simply aren't directly available as selfhosted replacements", a message queue is pretty basic stuff.
I'm super into self-hosted shared-nothing queue services, but what AWS is doing with SQS is anything but basic stuff.
It's not limited to some. You absolutely need a whole new team (or teams) to handle your infrastructure, your high availability needs, and also your security.
The nifty serverless offerings and other features are just nice-to-haves in comparison to the core infrastructure work that cloud providers put into your system to keep it running.
Just because cloud providers like GCP and AWS and Azure and etc have everything put together to let you setup your whole infra by running a small script that does not mean nothing needs to be done in order for that to work.
There are off the shelf things for, say, S3 and ALB which are entirely workable, but once you start getting into more complicated stuff (like S3's new consistency semantics, or SQS) then you're looking at a whole small company (at a minimum) worth of additional work. It's a non-trivial expansion, even for a large org with lots of money.
You can avoid using these sorts of services to maintain flexibility/independence, but you lose out on their unique benefits. This isn't an accident. It's not like you're going to be able to selfhost an SES clone and get the same kind of deliverability percentages as AWS netblocks, no matter how many engineers you throw at the problem.