I was confused because I only provided a different way to do the alignment, not addressing when it should be done
I would play this game with myself from time to time & depending on my mood could convince myself the derailleur was either bent or straight. So, for sure, I’m not going to be able to tell from your pictures.
I eventually bought a gauge for ~$40. It’s nothing special but it does the trick. I’ll link it below. Also, I think wolftooth makes a gauge that is very elegant…basically two tubes that are long enough to eyeball & know if they are parallel. If they are, bob’s your uncle. If they aren’t you’ve got plenty of leverage to adjust. But that gauge is a little pricey.
If you suspect a bent hanger, here is an easy test. Push your derailleur all the way into the big cog by hand, pushing as hard as you reasonably can. If your chain drops into the spokes, it is likely bent (unless the limit screws were already off and you’ve been magically getting lucky).
Replace the hanger and/or straighten it. So far I have only bent a cage once, and that was when a piece of rebar got sucked up into the rear wheel. I have tossed my MTB down some pretty rough crap and yet to ruin a derailleur, but I have been through many hangers (and many straightenings).