I use my printer to make prototypes for my business. There is no way in hell I'm sending them into the internet for some random to examine. I think my next printer will be mostly 3D printed, with a few generic parts like motor controllers, the odd bit of metal tubing, off the shelf bed levelling system, open source software etc. I only need single colour prints for work, and AFAIK the fastest printer on the planet is…
What you're looking for then is a Voron. They're the printers that Bambu was "inspired" by and are made with all off-the-shelf parts.
I really enjoyed building my Voron 2.4. I bought a kit that included all the wires pre-harnessed which made it much simpler to do.