[LeonM]

Stripe is fairly straight to set up if you sell products in the US and only accept cards.

For selling a SaaS worldwide, Stripe quickly becomes just as much of a nightmare. Taxes, billing, chargebacks, subscriptions, web hooks, different payment methods, VAT validation, card expiries, legislation, changing laws, SCA flows, and my favourite: SCA iframes that become non-responsive on browsers in a certain language. It is a never ending source of edge cases.

Don't ask me how I know... My biggest mistake with my business was that I vastly underestimated how much work it is to accept payments. In my case, it proved to be more work than building the product itself.

[biermic]

Exactly that. While stripe would tick my needs, it's gonna cause some headaches on the long run. They can calculate the taxes meanwhile, but you have to still take care of e.g. MOSS yourself.