The Lions were put in kind of an impossible situation with Goff. He's been too good to just cast away, it's not like we had some known improvement of talent to immediately replace him with (sorry Hooker), and the offense is largely built around his strengths and weaknesses and he just led us to the most successful Lions season that I've personally witnessed. On the other hand, there are clearly holes in his game and he's now being paid as a top 5 QB when his pure talent probably doesn't put him in the top 5. Nature of the business that the next guy to get a contract has to ping the ceiling, though, so this isn't surprising. I'll still feel better having Goff back than paying similar money to bring in Kirk Cousins as a free agent at this point, for example. Other QBs will get bigger money.
The big key is that it's clear the Lions are staking their claim that the next 3-4 years is going to be their big push. Let's hope it works.