[Si Coe]

Drivers with enough money have always had multiple cars. It provides a useful back up - sometimes they hide that by never building the 2nd car, just keeping it as parts but they have still paid for 2 kits.
Others went further and built that 2nd car up, sometimes even with electrics too. Let's say you were one of those and had 2 identical cars, but you set one up fully for grip, the other fully for high grip. You now have a wet and dry car, and an advantage over someone with just one of the same car. Why? Because whilst they could convert their car to be exactly like either of yours it will take time and is better done in a workshop than a rain soaked tent in a field.

This has always been the case. What has changed is that manufacturers are deliberately marketing cars for specific conditions making it more obvious. It's also widened the gap between extreme high and low grip cars, making the wrong one less competitive.

So this is not a current trend, it's just the first time people have been open about it.