Opex is faster. Login, click, SSH, get a tea.

Capex needs work. A couple of years, at least.

If you are willing to put in the work. Your mundane computer is always better than the shiny one you don't own.

Well, capex has a multi-year depreciation schedule and has to cover interest rates. So the simplified "opex wins most of the time" is right.

But we are talking about a cost difference of tens of times, maybe a few hundred. The cloud is not like "most of the time".

I think it wins because opex is seen as stable recurring cost and capex is seen as the money you put in your primary differentiation for long term gains.

It depends. Grant funding (e.g. in academia) makes capex easier to manage than opex (because when the grant runs out you still have device).