There is a word for this type of lie: vranyo.
Lying about believing that Trump will build a wall and make Mexico pay for it distracts you from addressing their actual motivations which they know are cruel and unjust.
I come from a very, very red part of America, and I can assure you that many of them do believe it, or at least did in early 2021. A couple years later, we've seen the investigations turn up none of the evidence that was described, but people still believe it. Close relatives of mine were raving about the 2000 mules documentary earlier in the year, which was completely debunked.
I think a lot of those same people are getting tired of being told that the next big shoe to drop is just around the corner, but if we're being honest, it's not all that different from how the left treated the Mueller investigation. Everyone was so convinced that they were going to rattle Trump's presidency and Mueller totally punted on Trump in his final report.
It feels like we're living in a non-stop JJ Abrams movie where we're constantly being triggered to follow one anxiety-inducing story after another.
The truth-tellers were expected to have an advantage: once the truth was seen, most people would recognize and accept it. The bullshitter's advantage was the slow speed of information diffusion.
Turns out that is wrong. People are regularly given definitive rejections of bullshit, and they deny them. It's not that they haven't seen it, but that they choose to accept the bullshitter's reality. We always expected to be able to fool some of the people all of the time... but we assumed that "some" was a number in the single-digit percentages, not a majority or near majority of the (connected, first) world.
I still don't know what to make of it. I'm pretty glum, to be honest. And I believe that's a lot of the point. I think that a lot of people choose to accept bullshit precisely because they think it hurts people they don't like. They may even grasp that it's false, but simply don't care. The negative consequences to them are sufficiently far off as to be dismissed, but the upside of having people angry at them is immediate.