You might not technically need it but some of the things offered by those services might be ‘nice to have’ for your specific use case. If they are not availab

You might not technically need it but some of the things offered by those services might be ‘nice to have’ for your specific use case. If they are not available with just Posgres+etc out of the box the few hundred/thousand $ additional costs might be entirely insignificant compared to the additional work-hours you’d need to implement those things.