These domains can work, they can and never earn. But they can only be used for official websites.
For example, Yandex and Google registered a lot of domain names that they will never use. They took them so that no one could use them and impersonate Yandex or Google.
Branch domains are intended for registration of third-level domain names taking into account industry, departmental and other similar specifics.
The branch domains are:
ac.ru - for research organizations; institutions of higher education; Cultural institutions, leading scientific research
com.ru - for business organizations
edu.ru - for educational institutions licensed for educational activities
int.ru - for international organizations
net.ru - for organizations implementing projects related to the development of the Internet
org.ru - for non-profit organizations
pp.ru - for individuals
For government needs
The administration of domains reserved for state needs is carried out in accordance with the rules and procedures established by the relevant state authorities. The domain names reserved for state needs include:
gov.ru - for the federal government agencies of the Russian Federation
mil.ru - for the organizations of the Armed Forces of the Russian Federation
For technical purposes
A number of domain names are reserved for technical and other similar purposes (in particular, for use as examples in descriptions, etc.). Such names include:
test.ru - for use as examples.
adygeya.ru - adygeya.ru - Republic of Bashkortostan (Ufa)
bashkiria.ru - bashkiria.ru - Republic of Buryatia (Ulan-Ude)
ulan-ude.ru - ulan-ude.ru, buryatia.ru, buryatia.ru - The Republic of Dagestan (Makhachkala)