Hmm fair point. I still feel with Pac-Man etc. the points roll on an odometer you look at the end, it's not a popup prize every time you do something right. But there's plenty of early examples, such as SMB's "1UP".

At least as old as Space Invaders (1978).

Nonetheless, meaningless points popping up on screen where the action is definitely went out of fashion for a long while.

I never cared at all about the points when playing either Mario or Sonic (although they were there, at the top of the screen): the achievement of beating the level was a much greater focus.