Unlike cross, MTB and road fan bases don't overlap much, but there are a lot more people following MTB than cross worldwide. I wouldn't say that very few actually care. The base is growing very much, but has the handicap of being held on sundays usually at the same time as the Giro, Tour or Vuelta weekend stages.
That said, although a G-W win would be bigger than an individual World Cup, I wouldn't trade one World MTB Championships or an overall world cup for a G-W. And some of his duels with Schurter of 2019 are there on the top of some of the most spectacular performances of his career.
Really? G-W is a nice win if you can't win RVV - but when you have a 4,1,2,1 record at RVV like MVDP, a win at G-W don't mean much. And I promise you 99.999% of the population in my country have no idea what G-W is, but a much bigger % of them ride MTB's and would be a lot more impressed by watching MVDP tear up a technical Elite WC XC course for 90 minutes than ride around Flanders for 5 hours.I simply do not know why hes so obsessed with MTB, even his biggest fans dont give a ***, but I guess he just loves it for some reason. Its a shame to waste time on discipline that very, very few actually care enough to watch outside the Olympics. Would it realistically add to his palmares? Not in my opinion. A win in G-W would be bigger.