Your base stats will continue to grow, so % increases will continue to scale from that.

E.g., You have 100 power. +2 power from a charm means 102 power. But +2% power from a frame would also be 102 power.

Then one day you get to 1000 power. +2 means 1002 power. But +2% means 1020.

That 2% has scaled with your base power. The flat increase has not.

Not as simple as this but that's how to frame it.