You can certainly connect your PC to the TV but as to whether it is as good as a dedicated monitor, in my opinion I would say definitely not. Does not come close. My Dell UltraSharp U2410 - 24" wipes the floor with my Panasonic 32" HD TV. Whatching videos or playing music is fine. I have not got a clue of how games look as I have never tried my gaming PC with the TV. I have no doubt others will have views on your question.
OnePlus 5T review: Hands-on