I’d been running couple TB mixed olap + oltp on 2016 a few years ago and a single cluster handled what otherwise today would be 3 or 4 different data stores today. Performance of properly tuned column stores was literally mind blowing. Haven’t even needed memory optimized tables.
Can’t comment on Sybase. Didn’t need any other platforms.
There were significant under-the-hood rewrites for SQL Server 2005 at least, and no doubt many smaller changes throughout the versions even where not adding new features, though there is still plenty that remains the same or at least very similar. I can name one bug from way-back-then which will never be fixed because maybe something somewhere “relies” on the odd behaviour!
Can’t comment on Sybase. Didn’t need any other platforms.