If you are finding the game unplayable on a PVP server the solution really is simple.
Roll on a normal (PVE) server. That’s where most people actually belong, whether they think they do or they don’t. That’s why Blizzard named them “normal” servers.
In vanilla, it wasn’t this bad because server populations were limited to 3000 or so.
This time it is what, 12-15000? In the same play area that was designed for 3000. Blizzard is not going to split or merge realms since that would be admitting they made a mistake in thinking most would quit classic and realm pops would normalize, else they made a mistake in thinking a 12k pop realm would work.
Either way they won’t admit they were wrong and take action.
BGs won’t help you much. You are still worth honor and even if you were not, once people get that taste of blood it becomes the norm. You don’t stop killing the enemy faction just because there are BGs. Red is dead becomes the norm. If you are on the underrepresented faction, with such high realm populations packed into the game area designed for a pop 1/5 this size, you simply will not be able to play.
If you do not enjoy this play style, cut your losses and reroll on a normal server, where you can choose when you pvp. This is how it is in retail now. War mode is modeled on how PvP flagging works on normal servers.
Again, most people are “normal” and belong on a normal server. If you have any concept of fair play, honor, empathy, not wanting to be griefed, you don’t enjoy griefing others,others, you like killing ppl once and moving on, not camping, not spoiling escorts or quests, or just in general wanting to treat others as you want to be treated, you belong on a normal server.