I use knobs everyday in my audio tools (with my track pad) and they're perfectly fine as long as they have three features:

1. Drag up/down to change value. 2. A modifier key to slow the drag for finer resolution changes when dragging. 3. The ability to double-click the knob and type in precise values when I know exactly what I want.

The problem with knobs on a GUI is when designers stay with them when there is a faster option. Like an opportunity to combine three knobs.

For example, the EQ on any SSL channel strip is a nightmare because they slavishly stick with a skeumorphic design of the original hardware. The hardware required mixers to use two hands to adjust gain and frequency at the same time, and then dial in Q on a third knob. Very tedious when you have a mouse.

When this is done right, you get something like FabFilter's Pro-Q graphic EQ. The gain and frequency controls are instead an X/Y slider that you can easily drag across a representation of the frequency spectrum. In addition you can use a modifier key to narrow/widen your Q. All with a single click and drag of your band.

> For example, the EQ on any SSL channel strip is a nightmare because they slavishly stick with a skeumorphic design of the original hardware.

True though I would put this very much in the "feature, not a bug" bucket. These tools are for people who have worked with the original hardware and want a very faithful emulation, including the look and feel. In the digital world with a modern PC there's not much purpose of a channel strip plugin in the first place, so the only people using one are doing so with intention.

It's a bit like saying that manual transmission cars could be controlled more easily if they were automatic transmission; it's completely true, but if you're buying a manual you want that experience.

Pro-Q is a great example of a digital-first tool (the automatic transmission equivalent), with lots of great visual feedback and a lot of thought put into a mouse+kb workflow. All of Fabfilter's stuff is like this actually, though sometimes to its detriment; the Fabfilter automation and LFO system feels very different from basically every other plugin. It's actually a more efficient workflow when you get used to it, but due to how different it is from everything else most people I talk to dislike it unless they've really bought into the Fabfilter suite.

Which kind of goes back to the original point: VSTs use knobs because it's what people are used to, and using something different might be a negative even if it's better!