OK, look - so you have a newish alt - you geared it through various ways (raid/worldcontent/crafting) and you want to start doing M+
Problem?
You have no key.
You can get a 2+ key from the NPC tho.
But you have like 465 ilvl and you don’t need anything like that.
You won’t be invited to groups tho, due to not so great ilvl and no rio on the alt.
You can, however, ask friends for help to skip the low slog and enter higher M+.
After completing this higher M+ you get a higher level key instantly.
So imagine you got dragged through 18+ - you get 17+ key you can “push on your own now”
But if you wanted to do it on your own from the start…
You’d need to run
2+ = end up +3ing =1st run
5+ - you need to +3 = 2nd run
8+ = you need to +3 again = 3rd run
11+ = if you +3 = 4th run
14+ - you are still in wyrm’s level - +2 = 5th run.
Now you are in 16s… after 5 pointless runs.
Even tho you are keystone hero on acc, you got portals in all dungeons, you can’t get a head start on alt without help from friends or buying a boost.
Now the funniest part - if you start 2+ on your own… and then somehow get invited to higher ilvl, your key stays 4/5+… you don’t get a new key for whatever reason.
So if you go head first to a higher key - you get a higher key - but if you are dumb and start lower or accidentally get an NPC 2+ key… you are done XD
I guess it’s not the biggest of deals but I think it’s designed in a pretty stupid way. a new player who never did M+ might need to start from the bottom but experienced players, not quite?
And then you DO have a way to skip starting from the bottom but it’s kinda leechy and silly.
IDK.
EDIT:
Extra thoughts - the game offers a lot of alt-friendly skips.
E.g. you can skip parts of campaign (that grant you some gear in the process - you can hasten it if you did it on main)
You can sometimes unlock something on vendors on main and it’s availble on your alts (see covenants in SL)
You can sometimes get BoA currency tokens to skip certain chores on alts (like Thorgast, “order” resources etc.)
You can, finally, get “free” or “paid” character boosts to get higher lvl and ilvl.
And most importantly - in raiding you are not limited by difficulty - you can head straight for mythic if you like and find group for it. You can even START the raid - in the past you had to clear normal to do heroic, remember?
Yet with M+ keys the system is stupid.