Believe me, I know what it does. At this point I would respectfully point to the fact that I've been printing for 6 years, have been running self-compiled Marlin for over 5 of that and have been fixing up the printers of 6 people in my friend group.
If your printer runs Marlin, your printer contains code I wrote.
I've been doing this for more than a few weeeks.
Also, you misunderstood what that guy before meant. He wasn't talking about simple Autobedleveling, but rather about auto-aligning multiple Z axies. See, if you have multiple powered Z-axies (e.g. if you have a bedslinger with two Z axies or a Cube-style printer that moves the bed along multiple Z axies), these Z-axies can become misaligned if one of them skips a step or you power the printer off and they become misaligned. There are multiple solutions for fixing this, and the guy before went for the nice but expensive route of controlling each Z axis with a separate stepper and homing each of them separately. That is what I said was a nice gadget, but not a must-have feature for a beginner.
Now regarding classic auto bedlevel: It's meant to correct slight misleveling and bent beds. It does so by purpously warping the print to follow the misalignment of the bed. This means, you'll end up with a print that is not straight. The reason why ABL exists is that 5 or 10 years ago, springs and beds were utter crap and thus people had to workaround in software.
In 2023, if your bed loses leveling all the time, you have the whole bed leveled too high so that the springs aren't tensioned correctly. On my printer I have to re-level the bed maybe 2-3 times a year and that's usually related to modifications like using a different nozzle.
Also, in 2023, if your bed is so bent that you'd need to use ABL to compensate, that's a warranty case.
If you actually don't RMA such a board but seriously try to compensate it's failings with ABL, you can choose between a fast 9-point ABL, which does nothing, a 16-point ABL which doesn't measure the center point, a 25-point ABL which does a bit more but takes forever or you go even higher and spend more time leveling than printing if you do small prints. Also, you need to re-level every time you print with a different bed temperature.
All in all: don't compensate mechanical issues in software. Fix your mechanical issues.