Why is Nano free?

Could you please elaborate on why Nano is considered free? Is it because there are no transaction fees associated with its use, or is there a deeper reason behind its zero-cost structure? I'm curious to understand the economic incentives and mechanics that allow Nano to maintain its fee-less model, and how this might impact its adoption and overall utility in the cryptocurrency space. Additionally, are there any potential drawbacks or limitations to Nano's free nature that users should be aware of?