Well there is a somewhat concrete way to determine this, or at least the lower bound. For a given set of games you’re interested in (e.g. FIDE games from the last 5 years for ratings from 1800 to 2200), how many ended in not draw or resignation but mate and didn’t have a blunder in the last move. There would still be more in the games that ended in resignation because they saw it coming.

But that may be the actual crux of what you’re saying. What level does one reach before they see it coming early enough to resign? I guess that is an interesting question.