The Sumo offer is really good: 1TB cloud storage for 98$

Transfer speed is good, website is clearly structured and I like the functions of the Windows app.

BUT:
stability of the Windows desktop app is horrible. I copy my photo folder (~100GB) to the mapped network drive and the app crashes in about 30 seconds. This is in my case reproducable.

So I tried the upload function of the web site "Add New". The result is, that the folder structure is "too complex". But what is "too complex"? The number of subfolders is not extreme.