Earlier quoted context omitted.
display_cc_form_that_handles_cc_data_so_we_do_not_have_to() { which_one = random_number(3) switch which_one { case 1: display_authorizedotnet_form() break case 2: display_stripe_form() break default: display_paypal_form() } } Plus the same integration work for each one that you'd have to do anyway (which may be little or none if you're using a platform that integrates all of them via plugins or settings or whatever)…
The problem is with recurring payments. If you used this approach and 1/3 of your customers were initially billed through Stripe, then if Stripe bans you then you can't charge the next month's bill through something else because you don't have the stored data for it, you have to ask them to re-enter data in another processor's system.
Splitting up your payments reduces your volume with each one, which can mean you're paying higher rates overall. Or, if you go the "keep an unused alternative on standby" route, you'll likely at least have some initial traffic that pays higher public-pricing rates until you can convince them to give you a better rate, and put it in effect.
Still might be worth it as a kind of insurance premium, but it's something to consider.