The only caveat is that you need a domain…but I imagine most people here have at least one. You can upload up to 750GB per day, and download up to 10TB per day. There are ways around these limits, but the vast majority of people don’t need to use them. If you want to backup via CLI, check out @Mason’s script 
Alternatively, check out Duplicati which features deduplication and desktop support, among many other things.