I got similar info from my accountant. Along the Peddle and Lemon Squeezy she also mentioned FastSpring. Do you know anything about them?

Thank you for sharing your domain knowledge!

AFAIK: Lemon Squeezy is owned by Stripe and development is discontinued; I sold my software via FastSpring before I switched to Paddle, it is not very modern and you have to bring a lot of your own implementation; Paddle is quite easy to set up; more modern providers like tiun from Switzerland offer MCP so AI can do the setup for you (probably Paddle can as well)