It makes me really sad that Microsoft gave up on the windows phone as it had the best user interface and the performance was great. It was an easy to use third option to Android and IOS. Although not open source.
2 more years and Postmarket OS will be just as old as the windows phone was when it shutdown.
While I was more into Blackberry, the Windows Phone had the advantage of working well on slower hardware, which made them both cheaper and they maintained their battery charge longer.
Sadly both Apple and Google both dominated their app stores, leaving windows phone without many apps that people wanted.