Not in the scenario I described. You implemented a solution using lambda and api gateway. Hundreds of microservices later you may realise you could save considerable money going unmanaged. By that time your lock in is costing you an unhealthy amount of money and there is no easy roadmap to mitigate it.

Again, everything must be planned beforehand. Savings could also be marginal, but it could also be significant. In big enterprises, where billing is north of a couple of millions of dollars, every percentile you can save is justifiable.