The Bambu will have some sort of auto bed leveling. The simplest method is a limit switch connected to a small plunger style probe mounted next to the nozzle.
Whatever the specific method, the idea is something that lets the printer sample multiple points on the bed and use the Z axis dynamically to adjust for the small irregularities. If you don’t have that, even half a millimeter can ruin print quality, so the leveling screws are there to handle it manually from the bed side.
I'm pretty sure the original version of that printer didn't come stock with the CR Touch. So rather than redesign and manufacturer all new boards they just kept the same one.
Also, I have a BLTouch on my printer (same thing different name), and while it's pretty good, it isn't perfect, and I do have to manually adjust the bed a tiny bit here and there. My guess is, cheaper printers like the ender and my neptune that are designed with adjustable beds in mind are prone to the bed being thrown off balance, whereas nicer printers like your new bambu are more robust in that the bed is supported well enough to not get thrown off.
also, the springs tend to go out of level, and it's usually best practice with springs to level it manually and get it close enough first, then use the ABL to correct for the horrendous dip in creality printer beds.
I think some people do take them off if they have CRTouch and decent spacers, but the wheels still work as nuts, and then, neither CRTouch nor an Ender style bed is perfect, so if something is real wonky it can be good to make a few adjustments before probing. The Bambu was likely designed with ABL in mind, and at the price they're charging I'd also expect a little more fit and finish, LOL.
The knobs get you "close enough" and then the touch probe accounts for the rest. You wouldn't want your extruder to have to move up and down 1mm for each layer if it was really far off.
That's odd, I upgraded my ender 3 with bed leveling and removed the knobs to mount it fixed, because the damn knobs keep moving and then you have to redo the bed calibration. To be honest I can imagine one reason might be that a loosely mounted bed gives you more fault tolerance against the nozzle being too low. I put my bed on two parallel linear rollers for more rigidity, and combined with dual z screws the nozzle has no chance anymore to produce any sort of first layer when it is slightly too low. That made me realize just how much the stock ender 3 is flopping around, but also how this can give you mostly okayish results most of the time without having to deal with a ton of small tolerances.