As long as the support remains tied to the marksman, no, supports will never be able to be strong without ADCs being overbearing, because ADCs will continue to be the sole, or at least heavily majoritary, beneficiaries of the power of supports.
The problem right now with the way supports are balanced and designed is that it's almost impossible for them to not cater to the marksman. Beyond some supports giving stat bonuses that only truly work on marksmen (i.e. Janna's bonus AD and Lulu's bonus AS), support itemization as a whole is currently heavily focused on making the support give the marksman more defenses and more power. On top of this, marksmen are currently made to be the VIP of either team at pretty much all times, forcing the support to focus pretty much exclusively on them. All of this creates an environment where any power given to the support invariably bleeds over to the marksman in large part, so it's impossible to buff supports without buffing marksmen as well.
In order to remedy this, I think two things need to change: first off, the design and itemization of supports, particularly enchanters, needs to change so that they have the option to properly cater to any class, or just offer tools that any class can benefit from. We already have quite a few supports who could work very well with non-marksmen (Bard's good with strong, independent early laners, Ivern and Taric are great with durable melee champions, etc.), yet who can still succeed in a marksman-centric environment. Second, I think we need to start giving supports incentives to support more than just the marksman: putting non-marksman carries on the same level of priority as marksmen could help, and I think late-game champions with weak early games such as Karthus, Nasus or Veigar would very much appreciate the assistance. If supports get to assist their whole team, rather than just one member of a single class, they'd be able to benefit from balance changes without buffing or nerfing other classes along the way.
Because of this, I do think it would be possible to have a support meta, but League would have to change in a few respects before we can get there. I strongly believe in the possibility of an environment where supports help out more allies beyond just the marksman, and I think the only reason why it might seem unrealistic now is because we've spent so much time in a marksman-support duo bot meta that any change to it has become difficult to even imagine. A meta in which the support legitimately had to choose which teammate to help, which opponent to shut down, and which kinds of plays to make, is one where supporting would be significantly more fun and interesting than one where supporting limits itself to buying the same items and spamming utility on the marksman.
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or item 
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. Then even if one of these things are strong it usually just collapses into adcs being strong.
He doesn't cater to the ADC at all. In fact, his main focus is roaming, leaving health packets, and setting up ambush kills with his Magical Journey and his ult. His kit is in no way designed to specifically cater to ADCs, and in fact favors roaming mid laners and junglers more.
