The JJK anime is catching up to the manga. However, it's not quite at the same point. There are some arcs in the manga that haven't made it to the anime.
Overall, the JJK anime does a decent job of adapting the manga. There are some minor differences for the sake of animation and pacing, but they don't significantly deviate from the core story. Some fans might notice these changes, but they don't undermine the essence of the manga.
Sukuna does die in the manga. The way it happens is quite dramatic and ties in with many other elements of the story, adding depth and tension to the overall narrative.
No. Ryomen Sukuna is a fictional character from Japanese mythology and modern manga/anime. He doesn't have a basis in a true historical event or person.
Nope. Ryomen Sukuna has no basis in reality. It's a product of the creative minds of the writers and illustrators who designed a captivating fictional character for the enjoyment of the audience.