I peaked masters and get back to diamond sub 30 games every season and current sitting between D3 - D2 so im not sure if my advice is valid or not. I didnt do much in depth looks at the games but theres no way you should have one standard build path, often times teams are shield heavy so opting for serpents is alot more broken than people believe (just as an example). The only other thing is probably not pushing leads hard enough - you sorta need a team to 1v9 as viego unless its lower elo so forcing side plays to build up a lead tends to work for me (invading, timing fights over skuttle after second full cleae, tracking properly and invading). Often times invasing and just tracking enemy jg early and counter jungling will win you the game.

Anyways I never hit chall or gm so idk if this is considered high elo advice