What are the advantages of playing on a monitor vs tv

The biggest advantage is less input lag/latency. LCD TV's were notorious for having awful input lag when compared to older CRT's & computer monitors. Luckily most modern TV's include Game Modes designed to reduce input lag substantially. RTing's has a fantastic article written up to explain input lag, as well as some benchmarks comparing different input lag between TV's & monitors: https://www.rtings.com/tv/tests/inputs/input-lag. 

As for using a higher refresh rate monitor, there wouldn't be a benefit (yet). With the rumors of the PS5 supporting higher refresh rate gaming, it might come in handy in the future, especially if you find yourself jumping into PC gaming later on.