Make sense? I dunno. Works for my character concept? That's a different story. Say I have a barbarian, I envision them as someone who was raised as, but has rejected, being a Viking raider. So sailor make a lot of sense. The ability score bonuses are fine, I can take strength and dexterity. Skills of acrobatics and perception? Works for me. I'm okay with the navigator's tools even if I don't know if it will ever be useful.
But tavern brawler? It just doesn't fit. I'm a Viking, when we're on a raid, we're warriors not some drunken sailor getting into bar fights. It's also doesn't really fit my image of how I want my PC to work and I don't see it ever being useful. I already have navigation tools I may never use.
If I was choosing based on how I want my character to work the other backgrounds don't really fit either. Soldier is close I suppose, but it doesn't fit my backstory at all and I don't see my PC as being at all charismatic so intimidation will only be helpful if my DM lets me use strength on a regular basis. Also for characterization reasons I don't see him intimidating people unless he's actually raging.
In another case, the backstory is a paladin that was raised by a famous cleric. Dear old dad wanted my paladin to follow in his footsteps but it really wasn't a good fit and my PC never felt that particular calling. So Magic Initiate (Cleric) makes total sense and gives me access to healing word just in case since we don't have a dedicated healer in the group. I want my PC to be the black sheep acolyte that never really fit in but was pushed into that line of study, the stat bonuses don't really make much sense. While charismatic, he's just average on intelligence and wisdom.
So some of it's optimization, some of it's just how I envision the PC. In particular, the origin feat looks like it will make a pretty big difference in how the character actually plays out but I'm SOL if the origin feat doesn't match the ability score bumps that make sense to me.
