Arms warriors are only good if you know how to play them correctly. If you just log in with one as an alt, and use a cookie cutter build off of icyveins or some other site that thinks they know it all based on statistics, you’re going to suck and get frustrated.
There are only a few talent choices that are bad for pvp or arenas such as cleave.
Other than that
There is no bad choice, it is purely based on playstyle. If you want to get good at arms in pvp and pve you have to go through a system of trial and error to figure out what works best with how you want to be a resource for your group.
A good way to do this is spend time in front of various training dummy’s. Pick a talent spec you like most, and attack the dummy for about 3 minutes and look at your dps, then go to multi targets.
Then change 1 talent, and see how it effects single target vs multi target vs pvp target.
After about an hour after taking notes, you will end up honing in on what talents work best for you and then you have to add in utility.
To do that, if you want to do battlegrounds you have to try a couple, one time try storm bolt, then try using 2 charges of charge, try out second wind.
Think about what you want to do, chase healers? be a flag carrier? node defender? there are specific talents to help you out with whatever you decide you want your specialty to be in the battleground
There is always more to do than just the dps meter, however, if you want to get that thing cranking i suggest using warbreaker in combination with a bursty trinket, avatar, and bladestorm.
-Thats probably the best combination for extreme burst dps every 2 minutes or so
Also, azerite gear and pvp talents can greatly change your utility or single target damage, sustain damage, burst, survivability etc.