cloud native services

The best way tolook at it is to compare with what you would do on-prem. Sure some services (e.g. serverless ones like Lambda) wouldn't have a role on-prem soyou can think of the as cloud native. With other services though it depends how you use them. If you just did a plain lift-and-shift of a 3-tier web application from on-prem to cloud with all tiers running in EC2 then no, that's not cloud native. However if you used RDS for your DB, made your other tiers use EC2 Autoscaling with immutable instances, and leveraged AWS services for session store, authentication etc. in ways that aren't possible on-prem, and that leverage the flexibility and elasticity of Cloud then yes that's cloud native.