Maybe my point didn't come across properly. Me personally, I prefer to keep the org complexity down and externalize some headcaches if I can. Having to also manage hardware, people that manage this hardware and not being able to keep other people liable for a given SLA. It's just yet another thing that other companies are really good at and for me it's just not worth it to do on our own. If I don't really need it, why would I? And again, there are more costs associated with this approach than just infra vs hardware + people costs.

Granted, I'm never using edge/runner stuff and choosing the stack from the get go as something performant. I'm also talking about headcount < 100, which I also prefer to stay that way.

In short: it's not the background (I'm not the one directly managing hardware anyway!), but the upside is not enough for the risk, costs and headaches in general. You need to have a real good use case to do CoLo/DC. If you build web software, you probably don't need it.