I think there is enough push for perfection to make anyone feel like they're failing their dog on any given day. Sort of like the cosmetics and diet industry has done, making a profit on people's insecurities, I find that the dog training/obedience media explosion paired with people comparing themselves to something they read on the internet without knowing the writer's background is all in part breeding insecurities in the hearts of dog owners. The pet food industry is the equivalent of the cosmetics industry at this point.
Personally, yes, I feel I have failed a few times. I adopted too soon and without enough experience and ended up rehoming. I adopted for the wrong reasons and bit off more than I could chew, rehomed. I failed those dogs.
I currently have two that I'm settled on and committed to. Do I fail them? Sure, constantly, if I compare myself to the perfect internet dog owner, or a person that deems themselves superior. Obviously I'm failing them by taking the time to write this post; I'm literally taking, no, robbing them of precious quality time that could be spent with them playing or training, or obsessing over them.
At the end of the day, my dogs love me, I love them, and I do the best I can for them every day. I also have a family and other responsibilities and I can't let memes like "I'd rather be homeless with my dog than go to work and leave them alone bewildered and confused and traumatized by my absence" make me feel like a cruddy owner. Hyper rescue-types will make anyone feel like a terrible owner. Well, y'all get the point. I hope.
Just a big 'ole doggy FAIL over here.