admittedly you have no reason to trust me because im not high elo or anything but I do play a lot of support. This is by no means a meta defining pick, but its fun.

you can kind of think of support ezreal as an ap support. Your main goal in lane is to poke and kite. you should try your best to hit your adc and an enemy with your w, but one or the other is fine.

ezreal does well with poke and cc adcs like jhin and cait. I personally he is best with jhin, as he allows jhin to easily proc his w snare, as well as giving jhin a huge ad boost from ezreal's w. Ezreal's second best adc is probably draven, as they can all in together very well, netting kills for Draven. you probably shouldn't pick ezreal with adcs who are bad at kiting and or need a lot of peel. Ezreal can't really peel for his adc, even when he has slowing items. You shouldn't pick Ezreal into a high damage support like zyra or brand, as they pretty much do the same thing as you, only several times better.

as I stated, this pick is not meta defining, nor strong at all. But, I think it has it's niche within the current meta, even if that niche is really, really small.