When examining why corporations toe the line for conservative endeavors, it's less useful to examine the financial aspect and more useful to look at the power dynamic. Oligopolies are like dictators, in that they need to occasionally perform a tour de force, as a way to suppress the exercise of soft power. That is to say, scare the opposition to fragment them and to disorganize them, so they don't get any bright ideas. Inspirational Skeletor warns precisely of this: https://mas.to/@skeletor/117191580571928662

What soft power would Visa and MasterCard have been afraid of? For context, in the USA, debit card transactions are capped at a fixed rate per transaction, whereas credit card transactions can have both a per-transaction and a percentage. Accordingly, the card networks would very much like to be processing more credit transactions than debit. But this revenue comes off the backs of consumers, in the form of higher prices because Visa's fee is rolled in, even for people paying with cash. Enough clamoring about cost of living could easily put the card processors front-and-center before a Congressional committee, a spotlight they don't really want.

Such furore would have to be driven from both consumers and businesses complaining about the extortionate practices by the card processors. Which is why the card networks hide in one domain and attack in another: deflect to greedy banks that are charging high interest directly to consumers (thus ignoring the cut that Visa/MasterCard take), and then clamp down on one segment of businesses, as a sign that they can be vicious if any other businesses start blabbing to the feds.

The card networks assume (unfortunately correctly) that small and medium businesses will not band together to overcome these monopolistic moves. And the largest businesses that process the most card transactions (eg Amazon, Walmart) are so entrenched in accepting card payments that they already negotiate deals directly with Visa and MasterCard, so they're not a risk.

In the end, this could be viewed as a conservative cause that happens to overlap with a need for a naked show of force. And in that endeavor, they've succeeded: every platform that takes cards is on heightened alert, and that's a real chilling effect on the marketplace. What Visa and MasterCard can do to one business segment, they can do to any other. But I guess for now, most businesses are just pricing that in as yet another "cost of doing business".