[Sword & Shield] After 4 days I finally got a shiny machop, and it has an attack stat of 0, is it even worth training?

I've been trying to get a good semi-competitive shiny team but I'm still pretty new to IV training with breeding, after 4 days and 700 eggs I finally got my shiny machop but it has 0 attack IV's, is there any redemption here or should I just try to farm up a better one? If it's not worth using I'm probably just going to give up on machop and hope for the best with another pokemon

to be completely honest... your only other option is to obtain a bottle cap via battle tower. this isn't actually hard to do - assuming you have three decent lv 50 pokemon, it should be enough to at least defeat Palmer. 3 rounds at minimum + Palmer earns you 26 BP, which is more than the 25 BP needed for the bottle cap. assuming you're willing to stick with your machop and raise it to lv 100, there's your alternative. this is all, of course, assuming you're at post-game.

other than that.... idk. i'd hate to say farm up a better one since 4 days is quite a bit of time invested, but that's probably what i would do. unfortunately patience is needed to be your best friend here for optimal results.

good luck!

So I can give it a bottle cap and guarantee that I can max Machops attack IV and make it actually usable? I'm willing to train it to level 100, it'll take a hell of a lot longer to do that than it will for me to farm a new one lmao

Also yeah I've beat the game and got the national dex

yes. bottle caps more or less "fake" the 31 IV for the sake of stats. you're not teaching machop hidden power or anything, so for all practical purposes concerning it, yes "maxes" out the attack IV.