Chris Chibnall’s time running Doctor Who left many fans divided . . .

While not every story from his tenure was a failure, his era often felt safe and middle-of-the-road, and the Timeless Child storyline in particular remains controversial . . .
Given Chibnall’s history working with Jodie Whittaker on Broadchurch, his decision to cast her as the Thirteenth Doctor made sense — but that casting nearly didn’t happen the way it did . . .

Peter Capaldi recently revealed that when Steven Moffat stepped down, there were conversations about the show’s future that didn’t sit well with him. Capaldi considered staying on for at least one more season, which would have made him the first Doctor in the modern revival to serve under two different showrunners . . .
Ultimately he chose to leave, but had he stayed, the early phase of Chibnall’s leadership could have looked very different . . .
If Chibnall had taken over with Capaldi still in the TARDIS, there would have been no need for the soft reboot that comes with a regeneration . . .

The 2018 premiere, “The Woman Who Fell to Earth,” was written as a jumping-on point for viewers meeting a new Doctor; continuing Capaldi’s story would have required a different approach and likely avoided overtly reintroducing the lead . . .
Even so, Chibnall’s distinct production choices — from changes in visual style to hiring Segun Akinola in place of Murray Gold — would have marked his era as noticeably different from Moffat’s . . .
Casting repercussions could also have followed. Jodie Whittaker took on other work after her time on the show; if Capaldi had remained longer, she might not have been available when the role next opened . . .
That raises the possibility that the Thirteenth Doctor might have been someone else entirely, reshaping the show’s direction yet again . . .
In short, Capaldi’s decision to leave opened the path for Chibnall to introduce a new Doctor and a new creative tone. Had he stayed, Doctor Who’s landscape in the late 2010s — from storytelling to casting — could have been significantly altered.
But without a time machine, we’ll never know for sure.