I guess that stupidity is not really a good identifier. He's likely got a degree more than me, for instance. Intelligence, cleverness, or the ability to discuss the inanities of a ridiculous system aren't really the markers that should be merited. He strikes me as having little wisdom, which is of course entirely missing from UK parliaments, by design. It'd be unwise to think that there was a mechanism within those bodies that allowed for meaningful change, or even the slightest attempt to solve any of the crises that the system hurtles us towards. Look at @Ajja's list of "achievements" for labour for example (not criticising here). Have you ever seen such a bunch of lame, temporary, can kicking talking points?
What's that? The sixth mass extinction of all life on earth? Well, that maybe so, but have you seen that A&E waiting times are down to an average of 18 hours?
Representative democracy cannot deal with anything beyond the current. It's a terrible system. Someone suggested that social media etc meant that everyone wanted everything immediately and no attention span. That may be true, but it has nothing to do with the way the political system works. There has never been long term planning for any conceivably difficult obstruction, there has never been the chance to discuss what politics is for and what we want our communities or nations to be. You can discuss "the deficit", or "national debt", but never what money is and what it's for. You can talk endlessly about how we get economic growth, but never why. You absolutely don't get the opportunity to discuss civilisational collapse (and why ours should miraculously be different). Nor do you get the space to discuss all the issues and how they might interact with one another in a system - each issue is siloed off into its own discussion, so you can discuss climate change but not climate change with biodiversity or plastic pollution, and so you end up with the ridiculous solution of electric cars. Because you can't discuss cars, and you can't discuss what a city is and why.
Fergus Ewing is probably stupid, or not, but it really doesn't matter. Because Fergus Ewing is stunted by a system that dictates that he can talk about the effects of particular abstractions, but not about the abstractions themselves. Any wisdom that he might have is neutered by the environment in which he stands.
This applies to him, and the likes of Luxon or Ardern in New Zealand too, for the avoidance doubt. It's universal.
Edit: and I expect everyone knows what I've written above is true. But you/we will all get drawn back into discussing the political minutae as if it's "the thing", rather than face having to face the enormity of the actual thing. Keir Starmer being a useless dick is not "the thing".