For example, I found out about the local farmer's market in my city via advertisements being hung up around town, and that helped me get fresh produce and find some community. I'm not sure if I ever would have found that farmer's market otherwise.
I also found one job via a "Who's Hiring" hacker news post, and that's obviously an advertisement thread advertising open positions.
Of course, these do not balance out the negative impact of ads, such as advertising credit cards and sports gambling and gacha gambling games to get people into debt, advertising tv shows and movies to waste people's time watching garbage, and generally advertising garbage that makes people who were otherwise happy waste money and time for no real gain in life satisfaction.