Framerates weren't really a
Thing.
Before consoles had frame-buffers -- Because Framebuffers are what allow the machine to build a frame of animation over several VBlank Intervals before presenting to the viewer.
The first console with a framebuffer was the 3DO. The first console people cared about with a framebuffer was the PSX.
Before that, you were in beam-racing town.
If your processing wasn't enough to keep up with the TV's refresh rate (60i/30p in NTSC territories, 50i/25p in PAL) -- Things didn't get stuttery or drop frames like modern games. They'd either literally run in slow-motion, or not display stuff (often both, as anyone who's ever played a Shmup on NES can tell you)
You had the brief window of the HBlank and VBlank intervals of the television to calc stuff and get the next frame ready.
Buuuut, as of the PSX/N64/Saturn, most games were running anywhere between 15 and 60 FPS, with most sitting at the 20s.
PC is a whole different beast, as usual.
Wrong but also not completely wrong.