Looking at the 1974 arcade game Speed Race, I notice that the cabinet includes ancillary LEDs to show the scores.
That reminds me of the Wozniak version of Breakout, which likewise used an ancillary LED. Atari wanted the score shown on the CRT instead, and they couldn't figure out how the design worked, so they scrapped it and redesigned from scratch, though the redesigned version did not match Woz's economy of components.
(This was not Woz's fault; it was the fault of the arrangement where, instead of the company talking directly to him, Jobs was the middle man in a game of telephone. It's an example of why design by 'toss the requirements over the wall, get a completed design tossed back' doesn't work. There will always be something you forget to spell out in the requirements, always something that needs to be adjusted.)
And I've been wondering, if Breakout ended up showing the score on the CRT, why didn't Speed Race? It's not because the technology of 1974 wasn't up to it. Pong showed the score on the CRT in 1972.
Conjecture: it took significant effort to design a compact circuit to show the score on the CRT. Perhaps the ancillary LEDs added manufacturing costs to Speed Race, but made the design easier, thereby achieving faster time-to-market? That would require the LEDs to cost more than the saved logic gates, but if that's not the case, then I would expect at least one of Pong and Breakout to use LEDs.