The important thing to know about dynamic contrast, which isn't clearly mentioned in the wikipedia article, is that monitor manufacturers measure it by comparing an all-white screen with the backlight turned up to the maximum to an all-black screen with the backlight turned down to the minimum (or even off). With dynamic contrast turned on, the screen will auto-adjust the backlight based on what's showing, but all-white or all-black is so rare in actual usage that the dynamic contrast is basically just marketing hype. Higher static contrast (comparing white and black that are showing simultaneously) is good, but looking for higher dynamic contrast is pointless.
The Samsung S20B350H claims "Mega ∞ DCR" (in case it doesn't show up in my post, there's an infinity symbol in there that doesn't show up on Newegg), whereas the VH236H claims 20000:1 ASCR, where ASCR is short for "Asus Smart Contrast Ratio", which as far as I can tell is merely an alternate name for Dynamic Contrast Ratio. However, the Asus VH236H has higher native resolution than the Samsung S20B350H.