She wasn't even that good then! For a short while I had a Nokia Lumia 520, it was a very nice phone, and Windows Phone OS was quite excellent. I enjoyed it while I could, and when it got the update to 10, I tried Cortana. It was like Google Now was in 2012. Couldn't toggle Wifi on/off, or Bluetooth on/off, or control smart home devices at all. It barely opened apps. It had issues understanding a ton. It was a glorified Bing search since that's what it ended up doing half the time!
Even S-Voice in 2012 could do all those things except smart home devices. I'm not surprised Microsoft has started getting rid of Cortana. I saw that coming when the Harmon speaker was discontinued.
For me voice control is convenient when my hands are full, or whenever I don't want my screen covered all over with nasty fingerprints. For that, Bixby on my S20 FE is excellent. It can do pretty much anything by voice. Something I clamored for back in 2012. S-Voice did a lot, but Bixby does far more. I'm probably one of few who actually prefer it over Google Assistant (although when I'm home, Assistant does far better with smart home and audio/video stuff)