I'm having a good time lately. I don't know what it is, maybe I'm getting better, maybe my expectations are more in line with what I can achieve. The latter may be where the OP has a problem. The game allowed him greater success in the past. It's hard to accept nerfs to your playstyle.

I personally have no problem with the existence of tanks and healers you can't kill 1v1. I vaguely agree that some specs, like my DK, are overtuned to where they can be extremely tanky and also do a ton of damage. That doesn't sit quite right with me, but how do you weigh the relative lack of mobility of such builds? My magblade feels a little weak, but she is a highly mobile build with stealth. I don't think balance is that far off. The last thing I would want is another haphazard balance patch.

The times where I can fight outnumbered on my magicka nightblade are exceedingly rare, but the times where the numbers are even and I thrive are becoming more frequent. Some things that cross my mind, reading the comments here:

If you can't kill tanky or healbot bad players, that might be because you are built for burst and not enough sustain. I've always run sustain builds and found that you can spam some people down, if you have the sustain to keep going. Burst and CC, of course, but you also have to be relentless. I recently killed a pair, CP700 and CP450, who were both tanky healbot types, healing each other. I think it was on PC NA, where I'm only CP650 myself. Granted, if they really knew what they were doing, I don't think that would have happened. Also this was one of the rare cases where the two had split off from their faction and I had time with them alone.

The other thing, when I hear people talk about siege - and maybe this doesn't apply to you, but it's remarkable how few people slot siege shield when you're pugging in Cyro. I've been toying around with Propelling Shield lately, which gives you more range to shoot back.