Those verbs need nouns. Cancel what? Proceed with what? Most of the time, it's possible to make buttons self-explanatory if you give some thought to the choice architecture.

Proceed seems to be the wrong verb here, as that dialog looks like it appeared after clicking a cancel button, and if I don't want to cancel I "return" to the previous screen where my data still is and don't "proceed" to somewhere.

That's what cancel does - you click proceed when you want to cancel. If cancelling isn't what you want, you simply click the button labelled "Cancel"

Clear as mud, right?

Well years ago at a convention I came across a little company that made Key caps out of Tempe, Arizona.

I bought a couple of bags of just two keys. Red panic buttons "Panic", and, "Any" keys.

We replaced the escape key cap with those when we sold new systems.

The "Any" key was a big hit and quite popular with the n00bs back in those AT (286) days.

I think I may still have a few of those around lolz.

I agree, but what's the use-case for such a dialog in the first place?

If there is a cancel button for a long running expensive operation it sounds like a good idea to confirm the cancellation.

Or if you are half way through paying for your cart, the merchant should check you really meant to press cancel.