Well, for one thing, Gamejolt asks for literally hundreds of vendors to sell my data to with that cookie warning. Itch does not even have a cookie warning for third parties. I did not find any amateur creators there. They state on their page that they look for established creators to bring existing followers to Gamejolt and get paid for that with advertisement revenue.
What are the requirements to become a Game Jolt creator?
Game Jolt users with 1,000 or more followers or users on platforms like YouTube, TikTok, Twitter, Instagram, Twitch and Patreon that have 3,000 or more followers will be considered.
I would not say Gamejolt is similar to Itch in any way beyond the trivial facts that some games are being sold there as well as on other platforms including Itch. I believe it once was a vastly different platform.