I suppose these “add-ons” will include exciting new features, such as the ability to install software from third-parties, and the ability to change their desktop backgrounds. In other words, things Windows 3.x could do.
I also suppose the “lifetime of the customer” meas “as long as the customer continues to pay for the exact same features again and again and again”. In other words, unless you are willing to pay subscription fees for several “add-ons” (each presumably available for a ridiculous price), the OS will be so crippled, no one will want to use it. I guess there is gib money to be made in ransomeware.