I guess I'm talking about a cultural difference. It's been my experience that Access devs know when a problem is mismatched for Access (and move to storing data in SQL Server, etc). FileMaker devs seem to press on even when it's clear that the platform isn't capable of supporting their needs.
As one anecdote (of several): I support an instance of a FileMaker application w/ several 500MB+ "FMP" files, each of which take _hours_ to "integrity check" when the "FileMaker Server" process crashes unexpectedly. We talked to the dev about putting at least some of the data into an RDBMS (MSSQL, Postgres, etc) and they scoffed at the idea. It simply didn't occur to their mind that the platform might not be a good fit for the purpose.
Had Microsoft gone for a more custom interface like Filemaker instead of just nicely packaging up more general tools, my entire life might be very different and probably not better, even 15 years after having touched Access for the last time.