Consumer world. No need now to upgrade yearly or 2 yearly. Use what you have until it can't do what you require or the battery dies. Poco F1 user here now (4 months) after years (12) of top priced high end androids. Never again will I spend over £300 on a phone. Its madness. Look about and spend less time worrying about your phone if you can. I agree it's an essential item thesedays but too much stigma on high end technology and the need to replace it so soon isn't nessasary and the sooner you realise this the better.
Absolutely.
I think in the OP case, the thick bezels are reason for him to be tempted for something new. I would go for a new phone without bezels if I had that XZ Premium, no matter how great its 4K display is, and that it works with latest Android versions.
But in my case, I previously used a Sony Xperia S from July 2013 till March 2018, and now the VKworld S8 is from March 2018 till the present day.