Healer has been like this for 4-5 years, it will never change and I doubt 8.0 will fix it - the developers do not care because none of them are active healer mains and recognise healing is the least played role and has the biggest potential of gatekeeping everyone else if you're bad at it, so they intentionally make it worthless in casual content to please the other two roles.

If you want to feel needed and have fun on healer, go do content on day - week 1 where people will fuck up consistently and gear won't outpace fights yet, otherwise just accept this role is glorified insurance policy for dps/tanks if they somehow fuck up.

That's pretty much how I've made my peace with it, accepted healing is just a prog job for high end content, nothing more.