Reliability and speed. An Ender 3 will produce good prints if it's well tuned, but there are a lot of quirks to the design (mostly as a result of cost-cutting)

Reliability and speed. An Ender 3 will produce good prints if it's well tuned, but there are a lot of quirks to the design (mostly as a result of cost-cutting) that can cause problems out of the box and will cause problems over time. Prusa printers are far from perfect, but they're trusted by a lot of print farm operators to run 24/7 with very little attention. Modern CoreXY printers like the Bambu Lab or Voron machines are crazy fast compared to an Ender 3, without any real compromise in print quality or reliability. That isn't necessarily a big deal for hobbyists, but it's very useful when you're iterating on a design. For users who care about print speed, the issue is generally latency rather than throughput. https://www.youtube.com/watch?v=NFdfYn0DTUk https://www.youtube.com/watch?v=NFdfYn0DTUk