Can only agree. There is indeed no mystery about the popularity for modernIt's simple. Young drivers (sim drivers) aren't familiar with the classics. I grew up during the Ferrari/Ford LeMans battles. These to me are the ultimate cars. Can Am. I saw them at Watkins Glen. The 70's are the greatest Formula 1 years. I was at every F1 race at Watkins Glen from 69 till 80. Even the GTP years of IMSA. But you would have to be at least 40 years old to have seen and remembered them. Younger simmers have grown up with LMP/GT3/GT4 so naturally that is their cup of tea. I've been racing for fourty three years (learned to race in a Lotus 51 at Jim Russell racing school at St Jovite in 1975). Today I race a Vandeimen 95. The older the better.
GT3/GT4 cars in racing games/sims nowadays. It is really as simple as that.
In addition to this, the fact that by far the most (younger) people starting their
virtual racing "career" with console racing games like GT or Forza might be
another reason. Especially in Grand Turismo where GT cars and Prototypes
are core content and were highly advertised since the introduction 1998.