That's not what SFC (System File Checker) is for. Windows keeps a hidden folder that has a copy of all the critical Windows program elements. SFC compares what is actively in use with the contents of that folder and if it finds a non-match, it attempts to replace the active one with one from the secure copy folder.
So, if one of those programs becomes corrupted, SFC can usually correct the situation.
As for Microsoft and Windows 7.... Microsoft would really like to see Windows 7 die. They can not make money from it. It is the most reliable stable Windows ever built and will not easily die. There are still at least half a billion Win7 systems in use and I don't know about you, but I intend to keep using it as long as my computer can be made to work. After that my next computer will likely be an android hand held smart phone.
Windows Update was, I emphasize was, a very dependable excellent service that looked after security needs and occasionally added functionality to Windows. It operated for decades very well and was a respected tool. It was regarded as a must do process every month.
Back at the end of 2014, Microsoft fired all the Windows Update checkers and quality control people to save money. The result has been an ever-worsening parade of defective software patches and patches on patches on patches. Using Windows update now carries far more risk than not patching security issues that Microsoft finds.
In addition, Microsoft started using Windows Update to change Win7 systems to fit its needs. That became much more important to Microsoft. The user/owner was in 2nd place at best.
Defective Windows Updates affect Windows 10 as well. Only the result is much worse because Win10 offers no opportunity to the owner of the computer to decide what or when to update. Consequently Win10 owners are effectively beta testers in mass. Just this month Windows Update bricked hundreds of thousands of Win10 systems that have non-Intel processor systems. By bricked, I mean would not boot.
I for one, and all of my clients stopped using Microsoft Update altogether last May, and have no intention of ever using it again. Our systems are incredibly stable and reliable and we have not seen a single problem over that time on 150 PCs. As such, Microsoft's threat to stop "supporting" Win7 as of January 2020 is now meaningless, because we have already arrived at that point.
To Microsoft, Windows has become a strategic tool to meet its goals, instead of the powerful utility that served the needs of masses of owners who invested big money in the hardware to run Windows and the many applications that worked on it.