system
A chat on subreddit /r/pcmasterrace
human
Dual GPUs still have their place in industrial applications and machine learning, but for gaming having 2 GPUs is useless as there is literally only 15 or so games that support SLI and most of those games are real old ones from back when SLI got popular. For the average gamer, take the money you’d spend on 2 GPUs and get one better gpu as it will perform better for gaming undoubtedly.
gpt
SLI was always pointless unless you were doubling up the best card of the generation. 

And frankly even then it was mostly pointless. Only practical thing it allowed was 4K high framerates back when GPUs couldn't do such a thing yet in many games, but 4K screens started to be a thing. In most other scenarios the jankiness and problems that came with it just to get your FPS from say 150 to 250ish was totally not worth it.