Pixar Animation Studios decided to replace Tim Allen as the titular character for Lightyear, and their excuse for doing so explains why the movie is failing to connect with audiences as readily as other Toy Story films. Changing anything, no matter how big or small, about a beloved pop culture icon is always a tricky prospect. As Lightyear director Angus MacLane states in the behind-the-scenes documentary Beyond Infinity: Buzz and the Journey to Lightyear, "the stakes are even higher when you're taking a beloved character like Buzz Lightyear, and you're reimagining him."
Much has been made about how Lightyear is meant to be the big-budget blockbuster that inspired the Buzz Lightyear action figure from the original Toy Story. This idea certainly fed into recasting Buzz Lightyear according to Lightyear director Angus MacLane, who remains adamant that Evans was his one and only choice to play Buzz due to Lightyear being a spin-off Toy Story movie and not technically a prequel or direct continuation of the franchise that Allen's Buzz existed in. MacLane likely felt compelled to provide his reasons for replacing Tim Allen's Buzz after many fans were quick to theorize that Buzz Lightyear was recast in Lightyear due to Tim Allen's recent political stances and controversies.
However, MacLane clearly explains (via Vanity Fair) that Pixar wanted a more grounded take on Buzz for the film: "Tim's version of Buzz is a little goofier and is a little dumber, and so he is the comic relief. In this film, Buzz is the action hero. He's serious and ambitious and funny, but not in a goofy way that would undercut the drama. Chris Evans has the gravitas and that movie-star quality that our character needed to separate him and the movie from Tim's version of the toy in Toy Story." Yet while not a bad idea, in theory, Lightyear's mixed critical reviews suggest the new Buzz is far too serious in line with Evans' more restrained performance - and could've used some of Allen's signature Buzz wackiness to spice things up a bit.
Evans is a skilled actor, but his take on Lightyear comes across as a Captain America-lite of sorts - ensuring that taking the goofiness out of the character robs Buzz of what makes him so endearing in the first place. MacLane's view on Buzz seems to suggest that his main character has to choose between being funny or compelling, but a so-called "action hero" can be a source of comedy in addition to being the lead star. Look no further than Indiana Jones, John McClane, or almost any character Jackie Chan has ever played for evidence of this. Allen's unwavering bravado as Lightyear coupled nicely with his signature comedic delivery to turn Buzz into a fan favorite throughout the four Toy Story films. In contrast, Evans's Buzz Lightyear feels like nothing more than a generic adventure film protagonist, which may go some way to explaining why Lightyear failed to meet Disney's lofty box office expectations.
Recasting Tim Allen for the titular role in Lightyear wasn't necessarily a bad decision on its own, and having the movie be the basis for a beloved fictional toy is an inherently intriguing idea. However, in the process of updating the character, Pixar sacrificed too much of what made Buzz likable in the first place - meaning their excuse for replacing Tim Allen's Buzz is also why Lightyear fails.