The OLED panel blows away any IPS, VA, or TN monitor in terms of black levels and color rendition, sub-1ms response times, and plenty of brightness for true HDR.
There really isn't any disadvantage of OLED TVs in terms of pure image quality.
One disadvantage of OLEDs is a higher chance of burn-in with static images; that said, LG OLED TVs have been out for 9 years now and there are many built-in features that are designed to prevent this.