Nobody should have to put up with constant barking, any sort of constant noise nuisance can be unbearable!
Poor dog/s too - not being kept or looked after properly if the barking is that bad!
Ours bark a fair bit, terriers do unfortunately, but we try very hard to minimise it. A neighbour did complain recently, about Fraggle, but he had been overexcited that day due to visitors staying
We have been very careful since to make sure we bring him in if he starts barking in the garden - although I could have told that (new) neighbour that we've also found his screaming children playing in their garden, often late into the evening, quite invasive this summer. But didn't