I don't think a one level dip is atrociously bad. For example, let's say you want your Rogue to have once been in the army, and use a heavy crossbow. Well you could wait til 4th level and use a precious ASI on Weapon Master....or take a one level dip of Fighter, which also gets you Archery Style.
And the trope of "I was once an X, but changed my ways" is perfectly valid. If you can't do everything you want with a background, and the Feat system doesn't let you do something at 1st level (without forcing you to be a V Human), what other choice is there?
You might not need to multiclass to get the concept you want, but D&D has never been a system that lets you 1:1 create any kind of character you desire. Heck, some concepts make zero sense, if you think about it.
Let's say your concept is a former Wizard's apprentice who got kicked out on the streets and had to steal to survive. Here are your options-
Rogue with Sage Background. No magic for you unless you get it from your race, so you have to wait til level 3 to pick up Arcane Trickster.
Wizard with Street Urchin Background. This does thematically work, but if you actually wanted to play a magical Rogue, you still have to wait til level 2 and multiclass.
Without multiclassing though, "magical street thief" requires you to be a Wizard who can pick locks and stealth. Or wait til level 3. Or have your race choice locked.