It's even worse than that. Very, very few people are actually centrists. Like, .1% of the population are probably true moderates.

The parties are coalitions representing people of varied opinions. And people rarely agree with the parties on every issue. But most people fall generally on one side or the other. However, some folks end up highly misaligned to the party issue assignments. For example, what party is the natural home for a militantly homophobic militant atheist? They think both priests and gay people should be sent to reeducation camps. Where do they belong?Neither party really. This person would consider themselves a centrist, even though they have nutjob fringe views from both the right and left. This is an extreme example, but it illustrates what most centrists actually are. They're not lobotomized zombies with no passion or beliefs. They have strong beliefs that simply don't align with the party coalitions.

But this reality is not how "centrist" politicians govern. Instead they try to place themselves at the exact center of every issue. Very very few human beings actually think that way. So they inevitably come across as highly inauthentic. People believe in things. If you try to walk the dead middle, you're telling people you believe in nothing. You become a living example of the uncanny valley. And people feel gross just listening to you.

Combining the two: centrists have bad vibes because they always have an authenticity problem. They position themselves against change, but then happily go where the Overton window takes them (see Biden's outgoing border bill). They are for nothing except what they think is popular at the moment, which is usually out of date information, and that comes across as fake and focused on accumulating power rather than solving problems. You don't need to be a policy wonk to see that centrists will say anything to get your vote and do nothing to solve your problems

People did vote for centrism in droves a generation ago. It just happens that the system currently is no longer benefiting the voting public, so they voting public will vote for change.