Too many single item characters

((Please not this is in regard to 3v3 gameplay. I know in 5v5 is different ))

By that I mean chars that don't need to buy items to keep all their respective stats high.

There are just too many chars that can build flat damage and keep all stats competitive with no investment into them. Every game now there is at least two guys each team buying nothing but "big-sword" type item and staying competitive in all areas. They can run just as fast, Tank just as hard, absorb both magic and AD damage, and regen at super high rates with nothing but damage items.

It used to be -Didn't get good enough shoes? You can't engage on your terms or escape if you need to, or chase someone down. -Didn't buy health? You get forced away from a fight because you're on low health -Didn't buy armor? you're flat out killed.

Why are we seeing these perfect package characters all of a sudden?

The worst thing is all the older chars that need to invest in every single stat that they need to be viable just cannot keep up with some guy buying a sword every time he goes back to shop.