Like, «We require that your employees opens only links on white list, and social networks cannot be put on this list, and we require managed antivirus / firewall solution, but we are Ok that this solution has backdoor directly for 3rd party organization»?

It is crazy. All these PCI DSS and SOC2 looks like a comedy if they allow such things.

It's an absolute necessity: you can manage Windows updates and a limited set of other updates via things like WSUS. Back when I was at this employer, Adobe Flash and Java plug-in attacks were our largest source of infection. The only way to reliably get those updates installed was to configure everything to run the installer if an old version was detected, and then find some other ways to get it to run.

To do this, we'd often resort to scripts/custom apps just to detect the installation correctly. Too often a machine would be vulnerable but something would keep it from showing up on various tools that limit checks to "Add/Remove Programs" entries or other mechanisms that might let a browser plug-in slip through, so we'd resort various methods all the way down to "inspecting the drive directory-by-directory" to find offending libraries.

We used a similar capability all the way back in the NIMDA days to deploy an in-house removal tool[1]

[0] Symantec Endpoint Protection and System Center Configuration Manager

[1] I worked at a large telecom at that time -- our IPS devices crashed our monitoring tool when the malware that immediately followed NIMDA landed. The result was a coworker and I dissecting/containing it and providing the findings to Trend Micro (our A/V vendor at the time) maybe 30 minutes before the news started breaking and several hours before they had anything that could detect it on their end.