I just left a job that felt exactly the same way. Only problem is I let 6 years go by and now I feel I'm behind in the world. The company spent the last 8 years

I just left a job that felt exactly the same way. Only problem is I let 6 years go by and now I feel I'm behind in the world. The company spent the last 8 years trying to replace another 3rd party system. They're still to this day using the 3rd party system. It feels like such a waste.