People are complaining about ninjas from Edo Kage treasure being 2 stars, yet no one says anything about Iruka being way more powerful than Kakashi or GNW Tenten being stronger than any version of Neji.

It's not like they are capped at 2 stars forever, you can upgrade them. FYI, there are a lot of 2-3 star rare ninjas that are better than 5 star normal ninjas, stars don't determine everything.