It's probably better than being killed, but they're NOT happy, I don't have dogs in my house (really tiny by U.S. standards, normal by my standards) because it seems cruel to me (we did adopt two cats from shelters).

When I rented an apartment, a few floors down a couple had a German Shepherd, it was really unhappy and depressed all the time, it lived in a 50 square feet balcony.

It's really sad, but I can only adopt so many animals. Fortunately there are no kill shelters in my country, and shelters neuter nearly all the animals (my two cats are neutered).

I'm more worried about children in shelters (my GF works for the institution tries to find foster families for children that cannot be adopted, it's a really tough job):

I know its anecdote vs anecdote, but I personally know 5 renters in NYC with really happy big dogs :)

I never thought of it that way. It's clearly better to be a dog that gets left at home 8-10 hours on workdays than a dog that sits in a raised crate above it's own shit 23.5 hours per day.