Energy as a resource plays almost no role in gating champs like Zed and Akaili
I can't reliably say that I can take into account that a champ has no energy for me to engage. Champ like Zed/Akali always seem to deceptively have almost no energy and then boom, spams abilities.
It actively play no role in gating those champs. The actual cooldown of those champs abilities is actually more effective at gating them. You might as well make them resourceless riot because energy does nothing. If Akaili does it riot, she actually gains energy from her shroud.
I think season 9 riot need to take a hard look at energy as a resource and figure out if its actually gated those champs.