A someone whose owned a 4k120hz display for 2.5 years: The vast majority of the games you can play on PC right now are going to benefit much more from 4k144hz rather than settling 1440p144hz.
Sure, you might be thinking about Cyberpunk 2077 or Assassin's Creed Valhalla, but what about the first Witcher or AC Black Flag? Any time you pick up a non-AAA or few years old game, its going to massively benefit from using a 4k144hz monitor versus being capped at 1440p, especially with a 3080. Take a look at the Autumn Steam Festival and all the demos of **NEW** games you can play at 4k144hz.
I don't know your habits, but I'd imagine that a few years down the line the 3080 will be sold off while you'll still be using the same monitor.