Still losing games from having enchanter supports.

https://matchhistory.na.leagueoflegends.com/en/#match-details/NA1/3186433419/205601764?tab=stats

Is this the match you're referring to?

The one where you were Katarina mid with 3/6/1 and your Soraka support was 3/5/5 with the team kills on your side being 14? Stats don't tell us the whole store, trust me, but in this case you blaming a support seems silly.

She healed almost as much damage as you did.

You can't see shield statistics unfortunately, but if you click the more stats tab you can look at those other stats like healing that are just as important. It wasn't because of your lack of front line either, although relying on a support to fill that out is not going to work anyways. You had a Sion.

Katarina and Soraka have amazing synergy with one another because Katarina is a glass cannon and normally the highest value target. Soraka changes that dynamic. She sustains you in fights you'd otherwise lose, is the number 1 target on the team as a result, and her AoE silence/root can save you in so many situations. AoE silence is an incredibly powerful ability. Janna is also valuable to them for her disruption abilities. She can break up a bad fight, and well, glass cannons tend to get themselves in a lot of bad fights.

literally impossible to lose with janna.

If your losing becuase of an enchanter your teams front line has to be completely ass. Given how everybody mindlessly picking glass cannon "carry" champs in my games with no consideration for matchup. Blame the end of the season being near and folks panicking to climb more.