I paid for 200G icloud. I can't image who can store 200G with such slow and problematic syncing ?

I am totally frustrated. In the past two years, I never got my icloud drive cmpletely synced. It always says "pending item to sync". I tried a lot of ways. Remove all files. Factory reset my mac and start a fresh sync.... etc. Most of them only work a few days but then stop working right again. Most likely some fundamental files system logic is wrong.