Did you want a series of boba showing no development, flying around killing people for the entire series? It was made clear that boba learned about respect, and the value of a tribe/ family from his time with the tuskens. He wasn't soft, he had just learned more about how to rule. You also saw what he did to both the Nikto gang and to Cad Bane when he realized who killed the Tuskens.

It's not like Cad was poked with a switch blade and died. First of all, he is already passed the expected age of dying for Duros. He is extremely old, and considering his profession he is a beast just for still being alive. Second of all his chest was basicly punctured by a knifed mace. No one survives that, especially not at an age of 100+ for humans. He also managed to fend off a rancor on his own, without any effort which says a lot about Cad. And I love Cad Bane, he's my favorite Bounty hunter, but still it made sense for him to die in this way in a duel with Boba Fett.

And for Grogu, who knows what might happen. I think he might still return to Luke at a later point, but maybe after Mando has been to mandalore and learned about his history and maybe learned to wield the dark saber. Maybe Grogu will go to Illum at some point to find his own crystal, which would be very cool to see in live action.

Of course I will respect all opinions, so if you disagree, that's fine, but these are my thoughts.