Because he a kinda normal guy if you got rid of his abnormal strength he just a normal dude.
He stuck with a demon that dosnt give a shit about anyone he wants to see yuji suffer and you shit heads like Yahito who keeps on following yuji around making his life miserable.
If it wasn't for Toudou Yuji would have brokendown and gave up during the Shibuya arc.
If many of us were in Yuji shoes most of us would have gave up eariler then him.
MC like Naruto and Asta they are treated like jesus in there manga once all the stuff they were suffering from are gone there goals are outlandish that most of us would know if they weren't the MC realistically there chances of becoming Hokage wizard King is slim.
Yuji has a more realistic goal which is to eat 20 fingers and get executed but when he does he will die around the people he love like Fushiguro, Nobara, Gojo and Toudou. Which most people can relate to.