The maintainer's framing is the right one: do not try to be the next LocalStack, just keep the core services that were free before and keep them working. S3, SQS, DynamoDB and KMS cover probably 80% of what most indie devs need for a local dev loop. The sustainability question is different too. LocalStack's problem was trying to maintain parity with all of AWS while also running a commercial product, which put them in a position where the free tier kept shrinking to drive upgrades. A project scoped to a small surface area that does not change much can be maintained by a handful of contributors without burning out. The real test will be how quickly they respond to breaking API changes when AWS updates service behavior. That is historically where projects like this tend to lose users. Slow patch windows are frustrating in a way that makes you question whether the free tier is worth the setup cost at all.