small pumpkin man said:
The amount bonii you get from charisma isn't actually that high, and you can raise two stats from you level increases. So long as you have one attack stat at 18, and one at 16 you should be fine.
Assuming a point buy ... you can get a pair of 16's [with 4 points left over to spend]. With the correct race, that can mean you have something like an 18/16/14 for your "big" stats ... or two 18's and a 12 [could up it to 13 for feat requirements]. If you are able to wear heavy armor ... having DEX/INT as your "third" stat could be ok ... your Reflex suffers, but your AC is still pretty good [you pretty much need an 18 in your Reflex ability to make the armor better than heavy stuff ... it's just a matter of armor profiency to find the "best"].
A Half-Elf Warlock, for example, can have an 18 in both attack stats, with about 13 in Int ... unfortunately, that would give them bad AC. They could go with bumping up their STR enough to get into some heavier armor instead.
If you don't go with a pair of 16's though, you could instead have 16/14/14/13/10/8 ... which gives you 4 stats for the purposes of feats, a minimum of +2 for 2 saves and a +3 to the third ... before racial bonuses, etc ... You'd probably want your racial bonus to get the 16 to 18 and have that be your "main" attack skill ...
Certain classes are "focused" on a single attack skill, with secondary skills only relating to secondary effects.
All fighter stuff is STR Vs., for example, with the various other suggested things modifying certain powers [based on the weapon used].
On the other hand, you have cleric split down the middle with half being STR vs. X and the rest as WIS Vs. Y ... so it sucks for Humans ... you get a bonus at-will from the OTHER build type ... and you only get a single +2 so you'd only really be good at one build type in the first place. [Meaning there are definitely some classes better for humans than others ... namely the ones where opposing "builds" still have a shared attack roll ability.
[Also ... a sidenote. As was pointed out, STR is the main stat for many classes ... and outside of the Human ... only the Dragonborn can boost STR in the PHB.