Sure. It also makes it a lot easier for their work to be distributed for free across tens of thousands of people, who download things purely to avoid paying for them, like you're admitting that you do. But that only creates a net positive effect? What makes you think that, if anything?
Let's say those pirate simply didn't do anything. We wouldn't pirate it, it wouldn't be on youtube, or any other site: pirating and illegal music listening didn't exist all that shit.
Now, if I wanted to listen to their music, I'd have to buy a single or album to get into it. There is no place where I can listen to it freely or anything, I have to spend money. Some people don't have that money, or simply, like me, don't feel like spending money on it. Their potential fanbase shrinks A LOT due to this. Becoming big is hard and making money is hard.
Now let's go back to the current world. Someone has their music pirated or they just distribute it freely themselves. Much easier to get their songs now, no more financial issues that get in my way, so I'll say "ah, heck, why not" much faster and just give it a chance. This happens on a large cale, they get more fans quicker, become big quicker and sell more tickets to shows and such. They'll probably have more album sales too, because not everyone's like me and just pirates whenever he feels like it.