As someone who is currently working as a freelancer and used to work for an agency, I want to hear about your positive experience with agencies/freelancers.
The project owner, having never accepted that he did not have enough budget for his project, just blames the freelancer for poor quality.
Another thing is that it is about 100 times easier to sell someone a website or web application than it is to actually make it. So there are going to be people with marginal skills getting lots of business. And, even if their skills are not that bad, they may decide they need to sign customers even though they don't have the staff at that time. It can be easy for projects to go over scheduled time especially as buyers don't want to acknowledge the limitations of their budget.
The trick is to find someone honest. So start with a smaller project and if the communication isn't good or falters then you give them a short warning and then just have to fire them. Don't hope it will get better.
I think the best thing about an agency is that it typically has a locked-in personality and an obvious leverage point. If you can find an agency where you understand both of those pretty well, and you are a match for both of them in any number of ways, you are probably going to be a good customer, partner, owner, or freelancer for that agency.
So it's kind of easy to work with, or around, agencies with that in mind. Agencies also generally try (that is, people working at them naturally try) to avoid making things too serious or personal. I always appreciated that mindset in the way that it avoids some really common business mistakes.
Also I liked that agency employees are generally very aware of their emotions and are able to bring those emotions into their business projects. In larger corporations this can be super risky and is part of the appeal of working for an agency vs. a typical corporation, IMO.
Leverage point is where the personality is proven to work well in industry.
When working with another agency you are the customer so I guess you can’t really be objective how good some project was. We never did hire an agency when we thought that we get in trouble with delayed projects. We determine this by doing workshops at the beginning to check if we are a good match.