Here is my perspective as someone who has not started 3d-printing yet, but is interested to give it a try:

I'm a confused about the whole "3D printer sends prints to its manufacturer's server" issue. Because I wouldn't want to connect hardware device like a 3D-printer to a network in the first place.

Can I buy a Bambu Lab printer and just never hook it up to any network?

Will I be able to print from sd-card just fine?

Can I update the firmware from an sd-card?

If these two are possible, I would not have any problems with such a device. If they are not, I would not even think about getting such a device.

And when it comes to slicing software: Can I use any slicing software and all I have to do is load the hardware info of the Bambu Lab printer I want to use? Or do I have to use Bambu Lab Studio or a fork like Orca Slicer for some reason?

And while we are at it: Does command line slicing software exist? I wouldn't want to dabble with a GUI. I would want to define the parameters of a print job in a yaml or json file and then slice it like "./slice.sh config.yaml myobject.stl"