While the NTSC monitor I output video to was very forgiving, the RGB
display was not. The RGB display (the main target of the video
encoder/decoder system) would *not* lock (sync-on-green BTW) if the
signal was not within the specification of RS-170 -- including EQ
pulses. I tried to get the RGB display to work without them, but it
would not.
So as you pointed out... while there indeed, some devices that function
without EQ pulses, there are obviously still some devices that require
RS-170/NTSC as-written.
The video encoder/decoder chips I used are from Analog Devices
(ADV7179, ADV7181a). They are not obsolete. They allow you to
manually "play" with the synchronization over a wide range of
possibilities, but the chipset also has the proper NTSC as a preset
standard (as well as PAL, SECAM, and variants of the 3). If Analog
Devices still produces chipsets that produce video according to the
standards (TI and others do, also), that tells me that things like EQ
pulses are still needed.
I also built composite sync inside an FPGA, including the EQ pulses
(for possible future upgrades to this system).