What you have to realise is that the fail operational capability on the NG and MAX is a bit of a Frankenstein job (and a minor miracle that this was approved by the authorities) - two FCCs with two IRSs and two MMRs magically provide triplex redundancy. Reasons for a downgrade to LAND 2 may be that your ISFD is inop, that is the third attitude source for an autoland in this installation - also, if the rudder servo fails to respond to FCC commands during the self test the airplane won't be LAND 3 capable. The items you mentioned are supposed to be checked by the pilots, they are of course not all monitored - the airplane will even happily land on a single autopilot, not that Boeing would want you to try that
LAND 2 simply means that you've downgraded to a fail-passive autoland like on any bog standard 737 since the classics, not terribly restrictive if you don't need the last 50 feet of minimums.