I take it you've never played Kayle (or anyone with a Sated Devourer, for that matter)?
(EDIT: A cursory review at summoner profile appears to support my assumption)
Now, I will concede I am not familiar with how games in low elo (e.g. Silver tier) works, so I'll write this with the understanding you come from a certain... er... 'bias'.
Quick review:
- Kills/assists give stack (1 each)
- Scuttle crabs are worth 2 stacks each.
- Securing dragon for team is 5 stacks
Kayle is a decent ganker, provided your laner is not a complete idiot (read: pushing wave to enemy turret, failing to ward for themselves, and then getting gang-raped by the enemy jungler as a result), and has some form of CC.
You simply need to exert a bare minimum amount of pressure to prop up non-idiotic laners (the ones with mental deficiencies may or may not be beyond your help and control), thus ensuring their lanes do not collapse (as as a result, your jungle is not perpetually invaded/contested). Note that it is impossible for one to be in all 3 lanes at once, no matter how hard one a laner cries (i.e. they feed solo kills, cries about no help, etc), you must budget your resources (time and opportunity cost of clear paths and ganks) accordingly.
Even without any dragons and minimal/moderate kill participation (less than 3-4 kills/assists combined), it is a trivial matter to sate your devourer by 22~ minutes, provided you have good scuttle crab control (very easy to take early on, and still remain easy to take mid-game with the Krug-Smite buff).
Each item (with the notable exception of Nashor's tooth, also zhonyas if you are against an AD-heavy/assassin team) on Kayle costs about 2500 gold. This means that you hit item power spikes on a fairly regular interval. I don't need to remind you how fast Kayle annihilates camps (and champions) once mid-game rolls around, do I? Ranger's Trailblazer makes farming ludicrously fast and easy.