Why buy an EQ plugin?

Hey!

Come to think about it. As far as I get, an EQ just simply cuts and boosts frequencys, yes? So is there a reason for buying an EQ-plugins, instead of just using the free ones?

Enlighten me!

Only if it improves your work-flow. I made many null tests in the past and the result - between EQs - is positive (if you handle the settings properly). I use Cubase stock eq and, for colour and design, real hardware EQs (1176, API, Pultec…). That’s it.
Off course, if a plugin reproduces the right curve, there’s no reason to not use it if you can work faster.

For me is is ALL about the sound! work-flo is a bonus. It might help you understand how the “color and Character” can be shaped, this link it is JUST ONE EXAMPLE - one of my favorites the Pultec Pro EQ. A demo of why we like 3rd party plugs - https://www.youtube.com/watch?v=mwSlIo1IrDw
They can accurately emulate the vacuum tube “character” and “color” of a classic musical sound that we have all heard on hit songs. You do need to have pretty hi-end system and monitors to really hear the improvements.