I don’t see how this solution is in a red ocean? Mature offerings where? The only non-Latam alternative that comes to my mind in this space is Checkout.com and that is just partially similar.

A provider routing middleware with the goal of increasing authorization rates is likely not even an attractive business in markets like the US and Europe where you probably can defer to a single payment provider like Stripe for maximum checkout reliability.

This is not the case in Latam. Authorization rates are way lower and anti-fraud heuristics and models by local payment providers are less sophisticated. Most growing business in Latam end up in a situation where they neeed to re-route payments to increase their authorization rates and sometimes in the need to build very strict checkouts that harm conversions but that are needed to avoid a high volume of rejected transactions.