I will elaborate more in the replies, just be nice.
Tldr… I hate how one of the most common advice you receive as a loner without social life or a partner is to get a dog. I’m taking care of a dog for a while now as a favour, since I’m unemployed and have “nothing to do” (my brother went to his gf beach holiday house for the summer with her, his daughter, my younger siblings and my mom, couldn’t take the dog, it’s old) and I’m miserable, I HATE this. I don’t wanna have to deal with any animal after this.
Yea, that’s poor socialization, which happens a LOT with little dogs.
Most people don’t understand that many of the little dogs (the terrier breeds, notably), are pretty fearless and assertive (not necessarily in a bad way) by breeding. It’s all in the name “Terrier”, as in “go to ground” after small, rather aggressive animals (ferrets and such) .
That fearlessness and assertiveness needs to be conditioned while they’re young. Too many owners think the yappy little thing is harmless, so never train them to not bark constantly.
Honestly, about 90%+ of dog owners put zero effort into understanding dogs and their responsibility for socializing them.