If you can give the guarantees and convenience that lease web give, then yes.

Is your bandwidth unmeterred?

Do you have redundancy everywhere, including link and power?

Do you have software to remotely manage the server, including install, reinstall and emergency access?

Can I pay you with the company credit card? Do you provide a billing system with VAT?

If the answers are yes, then congrats, you can open your own hosting business.

But remember next year, the servers will be obsolete.