Chess and Go are brilliant examples of games with a minimum of rules which still lead to a maximum of complex game play full of deep ideas.
I agree. If you compare with Splinterlands, opening prep in chess are your cards. The rest are skill and talent. :)
... and the importance of opening preparation below international master level is overestimated. As long as you follow sound opening principles you can do rather well. Since many years (since I am not joining official tournaments anymore) I am not doing any serious opening preparations anymore and still easily keep a level between 2300 and 2400 rating in lichess.org.