Yes, they often run really close to the tyre. In my experience the tyre deposits clayey clag on them and that gets transmitted to drivechain, eventually (often pretty quickly) bringing everything to a standstill. It's why a lot of cross racers ran 1x before it was a "thing".
This is my favourite bike ever but it's pretty much a dry conditions only ride. It hardly clears 33mm tyres and soon clogs to a halt in the clag.
I don't like marketing guff, but I can see that a gravel bike can be a useful, adaptable, durable, all conditions, fast bike that allows you to cover distance at speed and explore the rougher stuff too - mixing it up however you like.
