108 heroes, with each 4ish spells ( possibly more, a hero has 14 )
100ish items
i still learn new stuff today.
Starcraft 2, just build a random unit and you can win in lower league so its much easier for nubs. And you can see in spectating, is just units pew pew each other, bigger the unit is, more powerfull it is.
Dota2 just has a big knowledge barrier, i don't think you can watch a dota game without breaking it. But if your new and play with friends that can carry you and teach you and you are willing to listen then its a lot easier game, but if there is nobody to guide you then its pretty hard.