More people to manage, more local governments with more layers of hierarchies and more bureaucracy overall and I've never heard of bureaucracies scaling well

If this were the case, Switzerland should be tremendously bad off. They have a ton of bureaucracy and are even more federalist than the U.S.

First of all, their point doesn't depend on Switzerland being in bad shape or not. They're not saying a country's situation solely depends on this, but that it's a factor. There are lots of other factors at play in Switzerland and most any other country.

Second, there usually is another layer in most of the US (and Canada, for that matter) which doesn't exist in Switzerland: the county. I think that's more likely to cause inefficiencies than federalism alone.

Also, I'm not actually sure Switzerland has more bureaucracy. It mostly seems comparable in my experience having lived in both countries. Are there any metrics on this?

Metrics? I thought we were all reasoning in sweeping generalizations here.

The Canadian tiers of government are very similar to the US. The one difference (AFAIK) is there is no "county" government or equivalent.

Anyways, this is actually the first time I've ever heard someone claim that Canada has less bureaucracy than the United States.

If everyone agrees with each other, then yeah, a large population is better. But when you've got a ton of people it's harder to find a solution that everyone likes. It's like the difference between two people trying to decide where to get lunch, and 30 people trying to decide. It also doesn't help that the West and East coast are culturally different, even among people of the same political party.

Isn't it more like 30 people vs 300 people? The proportions of differing opinions are are still the same in that case.

Your East vs West coast comment also confused me. I'd argue Canada has the same (or more) regional differences in politics.

There's the East Region (Ontario + Maritimes), Quebec (featuring a different language, heritage, culture and legal system), The Central region, and the West Coast.

Oh, and of course First Nations throughout (which of course the US has as well).