Real vendor-lock-in is caused by use of proprietary backend services like DynamoDB, Redshift, Kinesis, etc. which cannot be used anywhere else than AWS.
If you spin up servers to manage your database+storage needs, then you are no longer serverless, you are in a pretty nice hybrid - lowering somewhat your money costs maybe, but I'd still argue that the impact on ops of the "application servers" is negligible compared to what is required by everything else in the stack.
A lot of serverless apps use Graphql for this purpose since Graphql is backend agnostic.
The corollary to this could be that if you're not repeatedly pushing out MVPs, this newfangled stuff may not be that useful to you. This is my view of the full stack JavaScript world as well. Things are generally transient and experimental so the wild west stuff works fine there.
I'd love to be convinced that I'm wrong. I have yet to write a piece of software that has been decommissioned in less than a decade after going live and I do get a little envious of the fast moving stuff.