Why're we letting Zilean/Morg be a solo laner, but not Lulu?

All three have arguably similar damage patterns, in which they don't do much damage early but have decent cc with low mana costs, then their supremely high AP ratios come into play (Zil/Morg I mean) later on and they start chunking people (or even outright killing them) along with their also AP-increased utility.

Ie, damage -> tied into a form of strong cc Support -> shield (or revive) or Speed boost -> only for Lulu and Zilean Super high ratios currently -> Zilean, Morg, and I'm sure Lulu would still have some of her former damage before her many nerfs.

There's no continuity here. Lulu's a cockblock and 'oppressive' to Assassins and melee alike, what about Zilean who outright invalidates anyone's efforts provided he can press 'R' in time, along with doing a ton of damage when he can hit at least one of his many sufficiently low mana Qs lategame? His ult will very likely fully heal a moderate hp ADC too. His rework gave people the opportunity to get out of the way, in exchange for a stun if aimed right and an ult that has the possibility to completely revive and heal a champion. No wonder he was shortly picked up by teams.

Zilean especially loves to make Seraph's and/or ROA, so he can endlessly spam further. It's worse in ARAM where he already has nice regen.

I'm not biased for Lulu or anyone I mention here. I don't like any support-tagged champ that has enough damage to actually be a midlaner. So, I also don't like how the 'midlaners' Brand and Velk have passives and a cc pattern that lets them 'support'/off-carry. Infact, I see velk and brand more in support than midlane. Go figure.

How bout we make raka and nami a midlaner? Buff those AP ratios up to 90% and let's goooooooooo. Or make Ahri a support? The most elusive support you'll ever know.

I get that Riot wants 'MUH 15 CHAMPS WORLDS DIVERSITY' but this is dumb. And I know Morg hasn't been played in the LCS recently (unless I'm wrong in this). Brand, Lulu, Zilean, Zyra, and Idk about Velk, have been played in their 'off-role' to success throughout worlds and the past-LC$, however, from what I know.

Bring on the downvotes, to the people who read my name and instantly downvote. I'll keep making these topics though.