Is it only me but I checked out few Chromebooks from different brands (HP, Samsung, Toshiba) and their display quality is not as good as the one we can find even in budget laptop with the same price bracket (or slightly higher). I used to own HP netbook few years ago and its display quality is much better, crisp and deeper black.
I am wondering if this is due to the Chrome OS itself?
Don't think so. Chrome OS is just barebone Linux running Chrome browser. My Acer C720 screen is good enough for me — very bright and IMHO better than my old ThinkPad T410. It's no IPS though. The original HP Chromebook 11 supposed to have a nice screen and Lenovo ThinkPad Yoga 11e Chromebook has IPS with touch screen.