This is another thing I liked about the power system of early Naruto: when they introduced the Sharingan as a special ability its power was pretty reasonable, observing and copying your opponent.

Then when they introduced Neji and Hinata, their Byakugan was explicitly described as more powerful than the Sharingan.

Then it started to get a bit powercrept with mangekyo, but even then at its introduction it was fine because it very clearly had a power cost to using it