Why Microsoft reinvents Help file formats many times?

Question

https://en.wikipedia.org/wiki/WinHelp https://en.wikipedia.org/wiki/Microsoft_Compiled_HTML_Help https://en.wikipedia.org/wiki/Microsoft_Help_2 https://en.wikipedia.org/wiki/Microsoft_Assistance_Markup_Language https://en.wikipedia.org/wiki/Microsoft_Help_ViewerFinally their updated product (like Explorer) just open website or even Bing search result.

Someone · Accepted Answer

The first two pre-date the time one could assume disks and memory were large enough (help2 is from 2001; that’s Windows XP era; it required 1,5GB _disk_ space and 64 MB RAM) and people had an always-on internet connection, so data shipped on CD (later DVD; compiled help evening floppy disk, I think) and had to be relatively small.
The third has special features for CLI programs, and is much more recent, so I can see why they didn’t want to build on earlier work.
The fourth is the modern way. It makes fixing help easier (no updates to send out), and effectively doesn’t have space restrictions.