...Back then Revell was the so called "gold standard". ...
I think that's debatable. It really depends on the subject and scale. For example, Revell had established itself as the leader in 1/72 and 1/32 airplanes, in the US. And their ship kits, in box scale and then in their "international" scale of 1/720, had no real rival, at that time.
Monogram had 1/48 airplanes locked up. And Monogram's 1/32 armor kits were also top of the line, in the US, in the 60s and 70s.
I had the same experience with Tamiya, and Hasegawa, though, as you did. I didn't know anyone who built them, and that section of my local hobby shop was unfamiliar territory. I did start looking at Tamiya armor when I was in high school, and was impressed with the detail. But the 1/35 scale meant I couldn't display them with my Monogram kits in dioramas. And Hasegawa's ship kits in 1/700 were better than Revell's, with a much larger offering.
Revell eventually was going bankrupt, and that's why Odyssey Partners forced the merger with Monogram, which they also owned. Revell did have the overseas presence, though, while Monogram did not. Revell's plant in California was closed and production was focused on Monogram's facility in Illinois. While the combined catalog contained most of both companies' offerings, new development from that time on, was Monogram.
For car kits, I'd say Revell and Monogram were of the same quality, though AMT was the big car kit maker at the time, and in the US. Again, while there were excellent kits from Japan, like Tamiya's and Fujimi's, I don't think as many American kids were building them, at that time.
Today, if I were to recommend brands to a new modeler, I agree with those who say Tamiya, for airplanes and armor, but also old Monogram, for 1/48 aircraft, and Revell of Germany. Besides kits that are reasonably well done and look good, something simple to build while learning and improving skills is good. Someone new to the hobby should enjoy the build, with as little frustration as possible, so as not to get discouraged.