Very true, it was common to have over 10 coats of lacquer clear on a show car paint job. However, as one who was around and using a spray gun on 1:1 stuff back in the '70s I can tell you that not only was each coat of lacquer much thinner than one coat of urethane but the lacquer was color sanded every 2-3 coats to level it out. So the total thickness of clear on top of the paint was usually less than or equal to the thickness of one coat of urethane.
Clear is just a tool for achieving a result. It's a tool that can be misused, I've seen gorgeous urethane clear topcoats and I've seen horrendous ones. "Shine" isn't the only factor in making a finish attractive, a model or a 1:1 car can have a deep wet shine and still not look good.