Windows Defender will not silently remove the software completely, it will quarantine it and make sure you know about its actions (i mean, it does make sure you know it exists even when there are no issues by its constant "Windows defender scanned your system and found no issues" notifications).

At this point it is up to the user to decide what to do and most non-technical users will leave it at that (and wont know what else to do) which should keep them safe.