Switching is not free. If your team lives in Apollo’s sequencer and dialler, leaving means replacing three tools rather than one, and the saving rarely covers that. The same applies if you depend on its buying-intent signals or its Salesforce sync.
Apollo is a good product. The only real question is whether you use enough of it to justify paying per seat. If you log in, run a search, export a list and leave again — you are paying for a suite in order to use a database.