WebInfinity Plesk, for instance, is full price on its website, discounted at many web hosts, and free with web host, IONOS.com.
It's not "FREE". When a host offers a "free" licence as you seem to be making a point of, they are required to provide support with it. It will not be free to IONOS either, someone pays for it. IONOS will factor this cost in to their build and what they make extra over the cost of a retail licence or one someone may have to pay for elsewhere, will pay for any of the support overhead.
If you're offering a free licence and the host does not make extra money for that, you're expecting the host to then support third party software at the same cost as they were charging before...?
There is no such thing as truly free as in cost or as in burden. There is always a cost element, even if youre not paying for something.
Such a sweeping statement. There are many businesses that don't and for good reason. We don't and never will. Customers, like with Enhance, can try a service with the smallest outlay possible which carries minimal risk. If they don't like it, they are not committed and just cancel. Easy.