Webmin is a good free option to choose from. Hosting companies that offer free Cpanel is because they can afford a licence price, which is charged in the hosting price as an imperceptible small percentage.
When it comes to VPS you will rarely find a company that includes Cpanel with the box you are ordering, but depending on the price, licence may come "free" when above $15, $25, or $40 USD per month.
This is up to each company decisions, as many of them also offer different options to choose from either paid or free.