It really is simple story about one grumpy old man and his biggest fan. It does fit so nice as a Passing the Torch MCU show. Hawkeye(Jeremy Renner) is passing 50 so can't realisticaly be much of an action super hero much longer. So having Hawkeye(Hailee Steinfeld) replace him is only natural....and it did happen in the comics. (Though, sure, the comics have an immortal Hawkeye).
I've seen the complaint that Hawkeye is a guest star in the Kate Bishop show. But that is missing that both characters, Clint Baron and Kate Bishop are Hawkeye.
The show has a good mix of drama, comedy and action. And it does swing from light hearted to deadly serious. It's a good binge watch.