Generally people feel better about play Game Jam games in their browser, rather than having to download them. So yes do a Web Build, and make sure compression is off or else it will fail to play properly on itch.io. Zip your Build folder and upload.
Always test whether your game will work as a Web Build before thinking about how else to distribute it, as a lot of people will only play browser based games.
4000 entries, maybe 1000 submissions, its very understandable why people do this.
