She's presidential material but she should wait. Perhaps sometime between 2028-2036 would be better.
She needs a strong base of support and what would hers be? Pro-filibuster, narcissistic bisexuals?
She's the millennials answer to Bill Clinton and I think she'd be able to unite the party well, despite her relatively conservative positions. I doubt I'd vote for her, but I think she'd have enough support to win.
Bill Clinton didn't gain nationwide notoriety for blocking the entire Democratic agenda without even giving reason; except to politicos who remembered his '88 speech, he was a clean slate to Democratic primary voters in '92. Clinton was one of the best speakers in modern politics, with a unique ability to make his flip-flops seem genuine, his right-wing positions seem in line with traditional liberalism (see: his NAFTA and welfare speeches), and dodge scandals; Sinema doesn't even give proper interviews, and when she does, she doubles down on the reasons people hate her. Do you really think she can tell a voters she "feels their pain" and have them believe her? Would she even bother to tell people she feels her pain?
Clinton also won the primary in one of the weakest primary fields in recent years. If Sinema primaried Biden, then her most obvious base — centrists — are not going to defect from an incumbent centrist president, especially not for the Senator who blocked the president's trademark legislation. She wouldn't fare any better in a relatively open, Biden-less primary. The Sandernistas would make her public enemy #1, smearing her st every corner like they did for Buttigieg and Bloomberg. Generic Dems will stick with Harris. Being young and LGBT won't help her anymore than it did for Buttigieg, as most young LGBTQ people lean progressive, and the conservadems are more likely to be hesitant to vote for a LGBT person. Buttigieg is a moderate New Dem, but the base of his politics is still essentially socially liberal; Sinema's politics are Blue Dog in an era where all the Blue Dog voters now vote Republican — those aren't social liberals.