Which DNS server to choose for a domain?

Question

Domain Name System

For example, here https://habrahabr.ru/post/203292/ there is a list of DNS servers. Which one is better? Do they differ in speed/availability?
Can I select several different DNS servers at once so that if one server is unavailable, other DNS servers can get information from another server?
Can I specify different primary and secondary servers and maintain the same settings on them myself?
Do DNS servers initially refer to the primary or secondary server?
Can I swap primary and secondary servers? For example, it was ns1.example.com, ns2.example.com, and put ns2.example.com, ns1.example.com.
PS. Most of the users are from Russia.

Answer 1

if you are not going to start a full-fledged dns server secondori, and you have no issues with synchronization, then just delegate to Yandex, under the account for which the metric is configured.
Actually, that's all. The capabilities of the Yandex DNS server are enough for you.

Answer 2

this helped me netbreeze.net
from cloudflare I often meet Russian sites banned because of IP