Why doesn't Microsoft create a file system like Apple's APFS to optimize SSD based storage?

They did actually. NTFS is the file system that was developed by Microsoft, and is used to optimize flash/solid state drive based storage. If your computer is a Windows PC, then you're most likely using it right now and you just don't see it.

Apple's APFS, also known as Apple File System, was first released in 2016 and replaced Mac OS Extended to be the default file system for Mac hard drives from macOS High Sierra in 2017.

exFAT (Extensive File Allocation Table) was also developed by Microsoft, first introduced in 2006, and optimized for flash memory such as USB flash drives and SD cards. The reason you see it as lack of functionalities and obsolete may be because Microsoft wants it that way. That is to say, exFAT lacks many features 'purposefully' because it is supposed to be potable, and usable on more devices.

Let's put it this way. NTFS (New Technology) File System was released in 1993, and is only compatible with Windows. Though you can read an NTFS-formatted drive on a Mac computer, you won't get the write access. But things are different with exFAT. exFAT has higher OS compatibility than NTFS, it not only fully supports Windows, but Linux, macOS, and Mac OS X.

Including APFS, Mac OS Extended, NTFS, exFAT, and many other file systems, they all have their specific purposes for being designed the way they were. For example, APFS has some big improvements over HFS+, but it is mainly designed for SSDs, and for an HDD, formatting it as HFS+ would be a better choice.