Because you cant buy software once and get free updates for life that is not sustainable. Software requires on going development and maintenance so as a publisher we require a means to monetize the service we provide of ongoing updates and live support.
Now when your talking about a 3D model or similar sure that is static and rarely requires any updates. Buit for software and services, ya no … FAB is not fit for purpose because there is no means to monetize updates and support.
It is completely unreasonable to think you can pay 30-50 even 1000 and get lifetime support and updates. We have clients we have supported for over a decade, to whom we have provided thousands of hours of support and released hundreds of updates. we charge 100 for the base license and 20% a year for “maintenance”
Maintenance is optional you can keep using whatever you have forever if you like but if you want support or more updates then you need to pay us for our time.