Upon reflection your use of the term "friction" is a good one. Although I tend to look at "debt" as something you pay back as quickly as possible but sometimes you can only pay it back in installments.
I guess you could say having too much infrastructure friction eventually leads to one humungous infrastructure bonfire. :)
So... I tend to think of source control problems as being infrastructure debt, because you are definitely going to crash and burn eventually, and the longer you wait, the worse the problem will be. I am open to rethinking this, but I would classify automated deployment as being friction. If you can deploy by hand, and everybody knows how to deploy by hand... It seems that deploying by hand is probably friction while you are in development and then debt once the product is in “actual” production with end users. In development, you might make a mistake, forget a library, and fixing it is work but not catastrophic. But once you have actual users, making a deployment mistake could produce irrevocable disaster.
Anyways, just to be clear, I’m only bringing up the distinction for the sake of discussion. I like the post just the way it is.
There comes a point that even a tiny bit of friction, spread out over enough developers, eventually causes the marginal productivity boost of adding new devs to reach 0. That can happen even without friction, but the friction exacerbates the trend.
Debt and friction both accumulate, but debt must be "repaid" in a lump sum. If "technical debt" or "infrastructure debt" means your velocity is falling over time, it's friction, not debt.
Infrastructure debt would be something that is eventually going to cause everything to halt while you sort it out, and the longer you wait, the worse it will be. Not using source control is debt, because with near certainty you are going to have at least one major SNAFU requiring spelunking through backups to recover a lost file or to restore some prior release.
Developing without deploying at all is definitely debt, sooner or later you are gong to have to deploy.
OTOH, lot of "technical debt," isn't. It's just friction, and it takes some experience to know when it's a bad tradeoff.