Yet a lot of those businesses lean on the work of prusa.
Yes, a lot of the groundwork was done by prusa, and yes a lot of companies are standing on their shoulders. Prusa 100% deserves a lot of credit for enabling what 3D printing has become today, no doubt about that...but they haven't really been innovative or at the front of 3D printing for a while, they stagnated and have been overtaken as a consequence.
Edit: most of the cheap Chinese manufacturers are ahead because they lean massively in to klipper and rely on the community there.