Hello,
Your link to the Stripe Documentation is for "Stripe Checkout".
Stripe Checkout is an API to replace the checkout of an e-commerce platform.
Stripe Payment Method system continue to change and evolve.
The Stripe V3 plugin does have a partial support of payment method (mostly JS) but the main problem is that, this specific API is not (yet) compatible with "Connect" (marketplace).
Hopefully, some changes are in progress while it was just even mentioned 6 months ago.
On the other hand, Stripe changed some parts in the Payment Intent system which is not documented and requires to make further research to discover how their API is really working.
So while the payment method continue to evolve in order to be a real replacement of the "Token" and "Source" APIs, it affect the current stability of what is already in production.
Regards,
Jerome - Obsidev.com
HikaMarket & HikaSerial developer / HikaShop core dev team.
Also helping the HikaShop support team when having some time or couldn't sleep.
By the way, do not send me private message, use the "contact us" form instead.