Sounds like they could have labeled it "pay with card instead".
Edit: You could say something similar about any non-verbal cues. Why not say "error" instead of using a red error icon? Why not say "left" instead of using a left-pointing arrow? Etc. The answer is always that (if used appropriately) it lowers the user's cognitive load. Admittedly sometimes it's reasonable to use both e.g. usually you do say "error" in words too, and maybe your suggestion would also be useful for this button.