The characters in JJK feel more broken and more contrived despite at face value having a better defined power system than Chainsaw Man. The demons in Chainsaw man can basically do whatever they want with seemingly no bounds and can't even be killed
i don't think they are lonely in the same way, tbh i wouldn't even say gojo is lonely. tho nobody was comparable to him when it comes to fighting, i think he managed to connect with all of his students in some way, even if he was a terrible teacher; he successfully changed the world of jujutsu by educating the next generation, instead of just annihilating the current generation (which he could easily do). he felt lonely cause he loved fighting like goku, but unlike goku he had no rival, no friend with comparable strength and no enemy with whom he could go all out. in the end, he finally faced plot armor and managed to shine, showcasing all of his strength
