It is but much of that is overblown because of really old plasma screens - early 2000s and such. Some manufacturers dealt with it better than others. If you're buying an old plasma without burn-in after ~10 years of use with minimal attention you'll be OK. I make sure not to leave paused frame for longer than 30m periods and enable screensavers where possible. You sometimes can see contours of an image after turning off the TV if the image was still for some time but they fade away quickly and not cause any artefacts. Chromecast has a screensaver, my STB as well. Things like channel logos are not a problem even after long viewing sessions. I've had Panasonic and LG plasmas. They do draw much more power (150-300W) and in case of active cooling you can hear the fans just slightly but otherwise, to me, it's a steal at these prices for this image quality.

EDIT: I search for "panasonic plasma" and make sure it's at least 1920x1080 screen and try to buy it under $50, so far I've bought a few for family and one for the holiday cabin.

Plasma & burn-in: I have a '13 Panasonic Viera VT60 with 10,000 hours, no real burn in. I've got a '08 Viera and it's fine, too. I actually bought it with a vertical line malfunctioning, and it's seemingly sorted itself out (looks fine now). No dead pixels, no burn in, tens of thousands hours.

If I watch 24 hours of CS:GO, the white scoreboard text will be visible, but if I turn to max brightness/contrast and play Mad Max for 24 hours, it's always come back to normal.

The panels do get hot, though. That part's always been real.