I feel like these people make for terrible for coworkers. You'll build out a nice class or something that is being widely used and providing tons of value only

I feel like these people make for terrible for coworkers. You'll build out a nice class or something that is being widely used and providing tons of value only to discover for a new key component they didn't use your class, built their own to no real advantage. It's obnoxious. Another example. I did a proof of concept, demoed it to the big bosses. Got approval for it to be built. I'm not so much at the individual contributor level anymore though. Anyhow come to find the dev team didn't build off of what I started. Built from scratch and spent the first month reimplementing what I had already built. So dumb. Why do we keep doing this in our industry.