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Microsoft CEO Satya Nadella admits giving up on Windows Phone and mobile was a mistake
(www.theverge.com)
This is a most excellent place for technology news and articles.
As much as I dislike Microsoft, back in 2015 I used Windows Phone 8.1 for about 6 months and I absolutely loved it, the UI was so smooth and polished, even on low end phones, until WP10 came out and it ran like trash and I went back to LineageOS.
Microsoft didn't even provide a proper upgrade path for it's users. WP7 couldn't go to 8 and same for Windows Mobile 10.
Internally they were two very different things. WP7 was their old windows mobile with a new skin, while WP8 was the actual OS they had been working on for a long time. They felt the same but were very different. I guess they didn't think it was worth the hassle trying to figure out how to handle that update.
I don't know what was the deal with 10 though (I forgot it even existed tbh).