Exactly.
The framing of Manchin's views tend to be dominated by the left of the Democratic Party, who tend to call him a conservative or Republican-lite or things like that, almost to the point of it being kind of the built in assumption on his views.
But at the end of the day, while he does fall to the right of the AOC wing and maybe doesn't desire the same level of expenditure that they do, when you look at the guy's voting record, he's just not anywhere near being a Republican. And he's made it pretty clear a number of times over the years that he doesn't like Mitch and the GOP.
Setting aside that politically it would be dumb for him to switch parties now (especially given his Senate Energy Committee Chairmanship as well as his strong hand in negotiations on infrastructure), I just don't think the philosophical alignment is there. And while he can be a frustrating guy at times, I don't think he's unprincipled enough to throw out his beliefs to switch parties.... if he were, he probably would have done it during the Trump Presidency.