This article by Stephen King was first published in 1986. It is, I believe, still the best article on writing ever written. It lives up to its title in pretty much every way.
The fact is that an agent does make things easier. This does not, in any way, mean you can't find a good publisher without an agent, and more and more writers are going directly to publishers, and many are doing without an agent completely.
The primary reason an agent makes things easier is because agents handle the business side of writing, and most writers, especially new writers, don't want to take the time to learn the business side. This is not wise. Even if you have the best agent out there, you had better know the business side of writing and publishing just as well as she does.
Too many writers want an agent to tell them what to write, when to write it, and even how to write it. This is dumb, and pretty much assures, at best, a mid-list career.
It is possible to be published without an agent, even at many of the top publishers, if you know how to approach the editors. The business has changed, but what many don't seem to realize is that it's been slowly changing again, with more and more editors complaining that agents just keep ending the same old stuff they see all the time. This is often true. It simply is not in an agent's best interest to take chances on anything new and different, on anything that breaks the mold.
It's also true that while a few, a very, very few of the top publishers are difficult, not impossible, but difficult, to approach without an agent, the vast majority of books agents sell go to publishers that will look at manuscripts directly from writers.
More and more writers are going directly to publishers, and are using IP attorneys to handle contracts and other business dealings, and they're doing so for two reasons. 1. It allows the writer to be in charge of his own career. 2. It means the writer doesn't have to pay fifteen percent for life on every sale.
There really isn't anything an agent can do that an attorney can't. Or anything an agent can do that a writer can't, for that matter, if the writer takes the time to learn the business. Too many writers seem to think agents have some mystical knowledge or power when the truth is that many of the best agents out there knew nothing about the business, and had no special training at all, when they first hung out an agent shingle. All they had going for them was the knowledge of what makes a novel good. A crash course in how to handle a contract, and that was that.
An agent does make things easier, but an agent is absolutely not essential. And if you do need one, it's much easier to land a good one after you've had an offer from a good publisher.
I have nothing against a new writer getting an agent, if it's possible to land a good one. A good agent does make things easier. But it's just wrong to say that none of the top publishers will look at manuscripts directly from writers. Nor does it make sense to tell a writer than having an agent is the only way to go, even if it takes years to find one, if it ever happens at all. Quite often, it doesn't. There are more good writers than there are good agents, and certainly more good writers out there that agents are willing to take on based on the query system.
Agents are the ones buried in submissions, and even the best agent, even the hungriest agent, can usually take on no more than three or four new writers per year. They find these new writers based on an unbelievable number of queries, and it just does not work well for new writers. For agents, yes, it works wonderfully, but not for new writers.
Find a good agent if you can, but learn the business side of writing, take charge of your own career, and do not let lack of an agent stop you from reaching publishers. Publishers buy manuscripts, not agents, and writers sell manuscripts by writing ones publishers want, not agents.