I know many people consider Jango Fett to be a high point of the PT but IMO he's probably the single worst aspect of it. In George's attempt to cash in on Boba Fett's popularity he took everything cool about Boba and just gave it all to another guy only to say that Boba just copied him. That basically makes him another Kylo Ren/Vader poseur or TLC River Phoenix. That's a bad taste that I just haven't been able to let go of.
The part of your post that I put in bold encapsulates the prequels pretty well for me if you replace "Boba Fett" with "the original trilogy." By needlessly making so many PT elements retroactively connect to the OT, the prequels lost some artistic integrity in the process. And all for the sake of some cheap thrills instead of being for the sake of the story. There would have always been enough organic OT connections without needing to artificially create more.
Another Fett didn't need to exist in the Anakin act of the Skywalker saga ("Boba Fett worked, so let's do another one.")
A kid version of Boba didn't need to be in the PT ("People love Boba Fett, let's stick his origin story into the Anakin origin trilogy.")
Anakin creating C-3PO was a mind-boggling choice ("Wouldn't people be blown away if C-3PO was made by Darth Vader!?")
And other characters from the OT that had no story-driven purpose for being in the prequels (like Greedo and Jabba) just invite the question of "why are they in here?" Then the answer to that question cheapens the integrity of the story-telling motivation.
Worse yet, we just ended up with WTF scenarios in the OT like the fact that the two droids Luke came upon randomly in ANH just so happened to be created by his father (Threepio) and belonged to his mother (Artoo). Why do that!? And why present Boba Fett as a kid? The OT Fett was awesome, in large part, because of the mystery surrounding this masked bounty hunter badass who we know next to nothing about beyond what we see on screen and what we can gather from the implications of how Vader talks to/about him.
Was there ever an actual Anakin origin story that the PT stayed true to, or were the prequels more about Lucas recognizing that Star Wars could be used to build a cash-printing machine? When I watch them, it's hard to believe anything but the latter was the true motive for writing them.