bitcoin hold several around 7 transaction per second
the ethereum blockchain currently supports roughly 15 transactions per second
nano is better but
compare to
the 45,000 processed by Visa.\/
If you just care about transactions per second, you shouldn't use nano, but Visa. Faster more reliable and stable, tested, etc
If you care about decentralization, really being the owner of your funds, and giving back financial power to individuals, bitcoin no doubt.
Scalability is just a problem to be solved if people are using the network. People are not using nano or bch