This constant refrain about Anakin's attachments can be contextualized with Luke for comparison. Luke had attachments too. His aunt and uncle were torched to death. His friend Biggs died. His mentor "Ben" Kenobi died.
Anakin's mom (who he hadn't seen in 10 years) died when he was about 20 years old; that's the same age Luke was in ANH when *all* of his attachments died. And Luke had been with each of them in the past 10 years.
Having attachments lost while being a Skywalker who is strong with the Force doesn't guarantee a bad outcome, no matter how old they are when starting Jedi training. Luke's Jedi teachers were the same ones Anakin had. So this whole "Qui-Gon would've saved Anakin" business is just silly, IMO. Sorry, but I see no reason to believe it. It's just flowery language to make the story seem deeper than it actually was. The sad thing is how many people are eating it up like it's some game-changing revelation.
Because how different he'd be with Qui-Gon is nothing more than pure guessing. Anakin was created by the Force itself, and with a purpose! So his destiny was more his own to make than I think you're willing to concede. It wouldn't be cemented by which Jedi master survived the outcome of some duel with Maul.
And as far as the need for a father figure, the Force created/conceived Anakin with a slave woman who would have to raise him by herself. So, Anakin's destiny was intentionally meant to be fatherless, and all the while still be empowered to restore balance to the Force. It makes no sense for Shmi to be chosen if Anakin being fatherless would actually handicap him in a way where he'd be more vulnerable to joining Palpatine and becoming a Sith. Is the Force stupid or something?
If Anakin had been more like his son when making choices, his fate would've been different. And the fact that his son ended up showing him the right way to do things (having also lost his attachments *and* having the same mentors) is a pretty awesome story resolution.