Those are all use cases we needed to cover either way and we did, but errors were part of the routine more than exceptional events. In comparison Stripe was way smoother and documentation/support a lot easier to grasp.
But yes their documentation can be a bit poor around the edges and if you don’t really know what you’re doing
Stripe provides self serve with is nice for getting started and I’m guessing once you’re big enough to jump to adyen, you can likely get a discount on the sticker price since you have bargaining power
But for a $10M SaaS startup, this would come to $350k/yr (assuming some amount of non-credit-card and non-taxed payments). I would say at least 60% of that you would pay anyway to other payments processors, even doing all the software stack yourself (nothing is free in the world of finance, after all). So that leaves you with $140k p.a. for a software stack that covers billing UI, invoicing, taxes, financial reporting. It's far from obvious how you can come up with a comparable solution yourself with a budget of at most 0.5 developers and 0.5 designers that your $140k would get you.
The real question is how much do you want to put your eggs in a single basket. The company I’m at now has a multiprocessing setup that requires more work but isn’t completely dependent on a single provider.
stripe has a lot of value for out of the box integration, but if you're running your own custom solution you will need to put the same effort to integrate stripe at a 3x cost compared to adyen.
I understand it's a silicon valley thing and most likely those who use it don't get the same public pricing other people get, but aside from branding stripe is extremely expensive compared to comparable solutions.
and 4% of your top line is a huge thing to pay