In YC it often is. You are almost expected to prop up other YCs companies with your funds. If everyone buys each others services everyone can show their super duper growth and nobody lost anything (except VCs who invest later).
If your competitors can't pay their employees you can poach them for very cheap if they are desperate to make rent or mortgage payments. So more sensible competitors might even benefit from the stupider ones.
provided their main customer base is not from the area or the sector then it's pretty fantastic for them, especially if they had significant competition in their business model and many of those competitors are now insolvent