I don't mean to be rude, but have you worked at a very large company like Microsoft or Amazon or Google? Redundant products are par for the course because of the byzantine internal politics and funding structures of big companies.
There's this irrational demand vocal on social media that large corporations keep their products forever.
https://www.wired.com/2015/09/what-to-do-with-your-zune-rip-...
The company who STILL supports 16-bit apps?
https://www.groovypost.com/howto/enable-16-bit-application-s...
Ya... I would hardly say MS is known for killing stuff early - more like they've spent years being ridiculed for carrying baggage forward for decades longer than anyone else.
MS might be bad at a lot of things, but I'd hardly say they're known for "burning products with little notice".
- Business Contact Manager for Outlook, Outlook Customer Manager
- Microsoft Invoicing, Listings etc.
And these are critical applications for a company.
Have a look at Sharepoint which is widely used and has an uncertain future. Or the strategy behind Lync, Skype and now teams.
But we'll see. Microsoft has shifted in a good way in the last couple of years but their track record in keeping legacy operating system APIs for decades is not necessarily a good indicator of the stability of their other product lines.
Microsoft Invoice has transitioned to a cloud-based product, so again, they didn't end support. You might not like the new purchasing model, but that's very much different than them burning the product to the ground.
https://einvoice.microsoft.com/Default.aspx?MSIStateKey=f513...
Sharepoint is the backend for onedrive for business, and fully integrated in to Teams. What on earth would make you think it's going away?