Well yeah because at that point you're still missing Newfoundland and British Columbia
I understand your point, I do, but I think you may be missing mine. If you travel to every major city in a country sure you're going to be missing a lot but at the same time you're still seeing important stuff, and meeting a large number of people from every location. It's going to FEEL like you've been everywhere whether or not you actually have been everywhere.
Except we haven't even done that. I mean we saw tiny little bits of a few worlds. Including some major ones like Sur'Kesh and Thessia, sure. But these aren't (I hope) SIngle Biome worlds where you step foot on one and you've seen everything.
Even so, we haven't visited Kahje, or Kar'Shan. We've only scanned Irune and Dekunna. We only saw Palaven from its moon. How many major colony worlds have we visited? Eden Prime, Horizon, Ilium and...? How about turian colonies? or batarian? Have we really seen all the major Terminus worlds? Or the Traverse.
That doesn't even count the worlds we haven't explored in the Attican Traverse or beyond the Perseus Veil. Or heck, the outer edges of the explored relay network. There could be entire civilizations out there who fought their own wars against he Reapers, who developed completely separate from the Citadel Council.