Sans dodges 24 attacks before getting tired. Those attacks are a single simple slash. Sukuna can fire out a metric shit-ton of slashes every second via Dismantle. Even if we want to assume Sans can dodge Sukuna's danmaku slashes (When his best feat is dodging a single knife slash per turn, and IA is only assumed to work on a scale it's been shown too), he would become exhausted within the first few seconds of the match and then be killed after.
Sukuna spamming Dismantle on Yuji.
Sukuna literally slashing Geto's daughter into hundreds of tiny meat cubes
I mean look how he uses that shit in the anime. He can fire it off like a minigun. Sans isn't dodging all of that, and even if he does, he becomes tired after dodging 24 of them and then is immediately struck and killed.
Worst case scenario, Sukuna gets bored of Sans dodging, and uses Malevolent Shrine to make it physically impossible for Sans to dodge. Not sure why this is even really a debate. I feel Sans abilities are heavily inflated on the wiki even as an Undertale fan.