We should assume some "normal" level of stats. This brings two benefits:
Here's a proposal:
I know it's a little more complicated, but a system like this would definitely help establish a baseline for balancing changes that depend on stats. In particular, it prevents you from being able to easily "min/max" things like Str or Int, and if you really want to push them higher, you have to make big sacrifices. It also makes race and class much more important, since they let you bias your stats without the 2x penalty from point buying.
I think this would also need to be coupled with eliminating or reworking stat potions (just make them temporary?), otherwise stats can still creep really high.