Well I use it daily and I can't even scroll up through chat history without it getting totally janky. The search basically doesn't work, I routinely have to restart it and often text shortcuts (like Ctrl+A to select all) just stop working completely.
It's not stable at all. Audio calls are generally okay, but often screen sharing just doesn't seem to come through either.
I can't focus properly on bright blue things. There's a football stadium not far from where I live and its name alternates between red and blue in big text.
I know what it says but I cannot read it at night when it is blue.
No one can, for a bunch of reasons. The eye is mostly corrected for red-green wavelengths; the eye is a lot less sensitive to blue light; there are far fewer receptors for blue light, which reduces spatial resolution.
Monochromatic blue displays are an extreme UI antipattern and should not be used for anything. If combined with high luminosity, they become essentially unreadable unless close up. E.g. ultra-blue seven segment LED displays. VFDs can suffer from this, but this is also the reason why many of them use green-blue phosphors, and not blue phosphor (which would be possible).
Yeah, push notifications are an absolute shitshow.
A standardised push notifications API where you could swap out providers would be such a breath of fresh air.
That being said, the two applications I run that are doing long-polling sockets (Conversations and K-9 Mail) don't really use a lot of power, according to the battery settings screen on my Lineage device