I've seen Sybase being used by a product sold to telecom operators. If I understand correctly it's most important feature was doing distributed in memory analytics before stuff like Spark or Presto existed.
Back in the 90s Sybase was the only "major" database that SAP didn't support, ostensibly because it didn't support row-level locking, only page-level. Support for SQL Server 6.5 was added in 1993/1994 with the assistance of Microsoft (SQL Server also only supported page-level locking at the time and was still based largely on Sybase). Sybase ASE was only supported by SAP many years later, after they'd bought the company (primarily, I believe for the now-discontinued mobile products).