Indeed... I was very interested in Adyen, as it seems to be (for Switzerland) the only solution for running credit cards (POS + e-commerce) without having to install third party apps. They told me the minimum number of transactions was 5000/month.
It's sad that Odoo (out of the box) has no solution for small shops in Switzerland, and certainly in many others countries. I'm pretty sure there was a talk at Odoo Experience 2021 announcing a new solution directly from Odoo. I can't find anything about it in the videos of Experience 21...