Combination of targeted oil money bribery + whipping up tribalism, some explicitly sell their souls while others tie their self-worth to a lie

Having followers is a path to monetizing new lies against them in the future... best I've got.

Selling "secret knowledge" to stupid people has always been a profitable grift

Apparently twitter has a system where they'll pay you for posts with a lot of attention, regardless of it's quality. Pays less than minimum wage but some do it full time anyways.

The angle is having an ingroup. Build a community around absolutely anything and people will come, just so they can belong. Flat earth is just one of these. Flerfers are funny because it's so absurd, but the same psychology is at play for e.g. the manosphere, local sports teams and anything else if you look hard enough.
And they pay the bills via advertising. Another win for capitalism. Yay.

what's the angle

They want to make people suspicious of those who tell them that this year is the hottest since we started keeping records, and that is a big fucking problem that will probably cost us every low lying country and every coastal city and every beach

In Kim Stanley Robinson's near future sci-fi people dredge up the old beaches to build new beaches

Engagement bait. Algorithm recommends them to more people. They get more money from ads.

I'm convinced none of these people actually believe this stuff and they just think they are being funny

The best way to find answers online is not to ask a question. Instead, it’s to make a statement that is wrong and wait for someone to correct you.