How to transfer data (contacts, purchases) from one android account to another?

Question

Android

I have a tablet and an android phone with an account "attached" to my domain (for example, [email protected]). How to transfer all data (contacts, purchased programs and music) to another account - for example, [email protected]?
Suppose contacts are not a problem to transfer, but here are the purchases.

Answer 1

Purchases are tied to the mail. If purchases were transferred between mails, then everyone would have had everything for a long time, maybe they would transfer everything to friends, friends of friends, etc. What is the problem to attach 2 devices to one mail?

Answer 2

Purchases cannot be transferred from one Google Account to another, but you can install under a different name. To do this, log in using the required account in the Play Store and download the previously purchased application again.
https://support.google.com/googleplay/answer/11341...

Answer 3

Linking 2 devices is not a problem. It's just that the point is different. I want to transfer the [email protected] domain to Yandex mail, since on Google you can’t use more than 5 accounts for free, but I don’t have enough.
But if I transfer the domain to Yandex mail, then the android (probably) will stop logging into the Google account. So I want to transfer both devices to a gmail account.