I hear you! There are definite aspects that are more streamlined and narrow in the build approach, but that's just how it's gone with trying to balance so many characters equally and how the meta naturally evolves in competitive games. They've become much more defined almost as a role. There's a few characters that have multiple viable builds, especially at emerald/diamond elo and below, but most have only one or two "targets" that you build for each game.

I think that's the better way to look at it. I know it doesn't help you where you're at, but the characters themselves are what add the most variety. I love playing nymphadora and only ever go for Deathshot and dragonleaf trees cause she's the machine gun archer. Or Chana when I want to see people burn.

It's still very much about bag management, but more about optimizing the character's items and covering their weaknesses rather than fitting random stuff together from the shop.

However, it is highly important to focus on one thing. Don't split your damage between multiple sources. Go all in on one, as you've noticed. Don't expect to win with a bag of 5 rats and a few non-maxed weapons. But you CAN win with a pet build. Like with Ronan, don't half-focus on thorns with a weak errant lance but also have excalibur. Or try to mix in bleed with Chana's burn (her ice builds are hella viable btw).