My phone was supposed to be Android 9, indicates iOS6, and doesn't function properly with security features. Can I switch out from the disaster OS and install Plasma?

If it runs Pie (9.0), it should have Treble support. I don't think there is a generic image for Project Treble devices (I wish there was but I don't know where to start porting that), but you should be able to install an Android GSI build.
https://forum.xda-developers.com/projec ... s-t4004673
Guide: https://www.xda-developers.com/flash-ge ... le-device/

OMG I got flashbacks of using Androids. I’ve been using one for two years and can’t say it was terrible, but still complicating sometimes. But I wasn’t going to change till the day I accidentally dropped it into the sink full of water. It wasn’t water-resistant and broke irrevocably. Seeking for new phone I got on a dedgoogled phones page. I bought one and have never regret it since. It’s easy to use, all the apps available and water-resistant (the last now important for me, lol). What phones experience do you have, guys? Mb smth funny? Anybody else got Pixel? I would like to discuss it