Using SNS as an example when it's neither micro nor a library but a service (and a huge abstraction over native push notifications, whereas most micro-libraries provide simple utilities that aren't very abstract), saying that complex libraries are harder to audit and hence a security risk (which should be a point in favor of micro-libraries that are small enough to audit in minutes), saying libraries might have large footprints (which is surely another reason to go for micro-libraries over all-you-could-possibly-need-libraries), saying transitive dependencies are bad, (yet again, this points towards an advantage of micro-libraries, which are less likely to have many dependencies), ... I don't know.
Using SNS as an example when it's neither micro nor a library but a service (and a huge abstraction over native push notifications, whereas most micro-libraries provide simple utilities that aren't very abstract), saying that complex libraries are harder to audit and hence a security risk (which should be a point in favor of micro-libraries that are small enough to audit in minutes), saying libraries might have large footprints (which is surely another reason to go for micro-libraries over all-you-could-possibly-need-libraries), saying transitive dependencies are bad, (yet again, this points towards an advantage of micro-libraries, which are less likely to have many dependencies), ... I don't know.