She sacked the ones who didn’t agree with her and squirrelled around to find some who did. She just wants people to agree with her. This is well known and reported by people who know her, and ably demonstrated by the confederacy of dunces she put around the cabinet table.
Her mistakes were ideologically driven, an ideology to which she is so wedded that it’s impossible to separate the ideas from the person. Even now, she still doesn’t believe what she did was wrong, despite the ample evidence before her. Whoever had done such a thing would have to go. Don’t forget that Kwasi Kwarteng, her partner in crime, also lost his job.
Boris Johnson is a vile, lecherous, venal man but he was too lazy to be driven by anything, least of all ideology, and so was happy to be a figurehead for whoever was buying him lunch/a holiday/a job once he resigned, and leave the hard work to people who knew how to do it. Putting Brexit aside (much as I hate to say that), the country bumbled along under his benign neglect in a way which was much less instantly damaging than Truss’s, which brought the economy literally to the brink of collapse within days of starting work.