I’ve read a lot about M+ but have yet to do any of it. My friends and I have been learning through the M0 dungeons to prepare for M+. The first week we got a key that obviously expired at the end of the week. I thought the key would be replaced with a new key for the week and the same + level. I thought progression in M+ was like a week to week thing where you would start at the same key level you left off at, but it seems we have to do M0 every week and grind the key up each and every week to wherever we want to be. Is this true or am I understanding something wrong about this system? Why would we have to do a +2 or +4 or whatever if we did them last week and are ready for something like a +6?
I guess my question is that every single week we are expected to grind up a key from the bottom to our max potential?