Your definition of horribly drawn must be different to mine. Sion looks brilliant in the sim, without any 3rd party scenery installed:
The DEM source data that is made available to Microsoft/Asobo will be at differing resolutions from the governments or agencies from each country as Jorg has mentioned on the recent developer live streams. He said Switzerland had the highest resolution, hence this topic!
Gosh some people are very hard to please… This flight in this topic was flown with a custom weather preset without any simulator generated surface snow. These textures seen on the ground are the Bing satellite imagery that will be present all year round. This is something you are going to have to accept if you want to see photorealistic ground texture coverage of (nearly) the entire globe rather than generic computer generated substitute textures as seen in every other global flight simulator up until MSFS. (Thanks for explaining this concept to Bam @Archer374 
)
For reference, here is a family photo of a visit to the same location IRL in August. Plenty of snow around at higher elevations 
Not sure what that has to do with this topic? Try visiting this thread and upvoting instead: https://forums.flightsimulator.com/t/snow-partially-at-low-altitudes-at-19-c-in-lowi
Right on the money again @Archer374! The vocal minority on this forum breath a huge amount of negativity into this community which is a real shame. None of the other long running FS forums that I am part of have anything like this posted on them and you can certainly pick those who are new to flight simulation here rather than long term hobbyists very quickly.
I guess miserable people tend to focus on the things that bring them displeasure where as happy people focus on the things they love!