OP, why is one topic not enough for you? Why are you creating multiple topics with the same question? Yes, many of us, being crypto owners, have used cryptocurrency payments in one way or another. There are many services for this, from Internet services to buying airline tickets in some countries.
But all your questions and your open topics come down to one thing: you do not understand the process itself.
Therefore, do not run around the forum, but stop at one topic where people can calmly explain everything to you, instead of collecting the same answers on different topics.

The majority of us did that. Even not so often but every one did that for the sake of experience, no doubt. There are too many crypto payment processing services and the most common term to them are the "third party" services that are being used by the platforms and marketplaces that we use that says they accept crypto but typically, Bitcoin and other top cryptos.