That is certainly true in my experience.
Also, some of the payment services have a habit of changing the appearance and/or behaviour of their hosted systems, sometimes not for the better, and typically without warning. That is a risk you might not be willing to take for something as important as your payment flow. I know of at least one local business that switched from Stripe Checkout to using Stripe.js from their own site as a direct result of Checkout being significantly changed and resulting in customer support enquiries about the new behaviour that the business had no idea how to answer.