Data cable needs for best performance. Cat X?

Question about data cable bandwidth.

Is there a data cable standard that would be considered 'future' proof - at least for current data streaming demands?

Is Cat 6a enough?  Or is Cat7 or Cat8 needs just around the corner? 

Not considering the differentials between manufactures and the differences in actual performance... but from a standard data pipeline pov... is Cat 6 standard enough? Or should one hold out until the boutique brands start releasing Cat7 / 8 data cables... 

I see many lauding $300-$1000 data cables... but as I understand it - they are cat 6 cables which is not the latest data standard available today... 

Has anyone actually done any a/b comparison between Cat6/7/8 to see if there is a real world benefit?

Unlike ICs - I don't see data cables being an investment if streaming more data will require upgrades in data cables every few years to realize the benefit of such data availability.