At the moment I am constantly surprised by how hard to read the maps are. I very often cannot see the roads because they are white no a white background (on my phone).

This was my reaction as well. It seems to be a fundamental shift from showing human boundaries (parks, etc.) to natural clime changes. Forget "more colorful"—that's a massive change in the intent of the data that seems to be glossed over.

Personally, I care much more about knowing where parks and public spaces are vs. whether the surrounding land is "arid, icy, forested, [or] mountainous".

Yeah, and does for example the white snowcap shown on Mt Rainier change with the seasons? How accurate is it at any given time, and if it's not accurate, what's the point?

In terms of usability, it's been said that Google Maps isn't about being a useful map application, but being a business directory with a map interface.