Sometimes it might be justified to complain about overpowered gear and skills, but before one does that, it is usually best to do the following first:

1) visit the websites of the best gamers in ESO, like Alcast and Sypher for example, and read what they have to say about using skills and gear to get the best result. Also study what more "mediocre" gamers write about the balance in the game from a more casual perspective.

2) accept that different classes have different roles, especially NB one can argue, so first check if you can learn to play that role properly, and if that doesn't work, then try to adapt and experiment until you find a personal playstyle which you can enjoy (no matter what others think about it).

For instance, my main is a NB, and I chose that class because I initially wanted to be a solo assassin in pvp. But it turned out that I suck at it. I read however that many gamers are really good at playing NB solo, so instead of complaining too much about NB being weak, which it actually is in several ways, I discovered that I'm one of those who actually enjoy being in a full pvp raid, running around the emp ring in Cyrodiil. With a best KD ratio of 148:0, and easily 50k ap an hour. So I love my little NB. Just adapted to what I could do with that class.

Another example: the eye of the storm ulti. Initially I and others in the ts guild complained about it, but then we adapted, tried to find ways to counter it, and lo and behold, the game was still fun. Now I find it a bit exciting to run like hell just one meter in front of a series of approaching fire storms. It's a tiny adrenaline kick when my vamp nb is one second away from being instakilled, and a dodge roll saves the day.

If you are a newbie (or more experienced) it's also wise to remember that if others laugh at your complaints, then the advantage of such toxic replies is that they hopefully sharpens your brain. Many laugh because they think you don't know what you are talking about, and that your complaint is one-sided. Try to learn from that. Be prepared, learn your stuff, and try to imagine how others will respond, before posting complaints. Sometimes that is easier said than done. I have often fallen in the "complaint trap" myself, and got flack from others afterward, some of it justifiable.

Usually it's best to study things and get a lot of experience seen from different viewpoints, instead of jumping to conclusions about what is overpowered. Perhaps it's just you (or me) who are unskilled.

In 2015 we in EP sometimes complained about Hexys playstyle/attitude when we fought DC. Initially I got a bad impression of him. Then it happened that I one day tried to gank a player on a horse in Cyrodiil. The first assualt didn't work. It was Hexys, when he was emp if I remember correctly. So I immediately stood still, and sheated my weapon. We looked at each other for two seconds, then I retreated and he continued toward Arrius, without killing me. I thought that was kind of cool.

War in real life is often not fair or balanced. But if an opponent got atomic weapons, you either adapt or die. Recognizing your own limits is smart, as always. But if one respects good players, most of them will be helpful and fair.

ESO is a good game because it's challenging. It's not a carebear game where everybody wins and everybody deserves a prize. It's a lot of things to study, like theorycrafting for example. Most people can enjoy it if they just find their own fun playstyle in this generally tolerant "hierarchy".