But you are already "established," you wrote several things that sold.
The narrative here is that you have to invest in editors before even one work is out in the wild.
No, we're saying that the major, traditional publishers, require you to have your own work edited. As you've undoubtedly noted, many first-time SOL authors don't even make the attempt to edit their works (i.e. they don't request editors before posting their works online).
IF you want to go the traditional route, you need to hire an editor. There is no other way around it. That said, those same authors don't have to worry about design or formatting, which is where I spend the majority of my writing income at the moment, because the publisher chooses to control that effort. They choose not to hire editors to help authors, but they have paid designers on staff, waiting for work.
The idea is that, if you want to write, you put the time into learning the craft first. For most aspiring authors, that means investing about ten years into refining their talents in school. Few of us SOL authors, who mostly turn to writing after we've already retired, took that route. For us, we either turn here, ASSTR or if we're younger Wattpad. There, you can develop your talents without investing large sums of money.
That feels more like a Pyramid scheme from the Editor "guild" Instead of getting paid by the publisher of the one book that gets chosen, they get to work on hundreds of scripts.
At one point, it was unheard of for an individual author to hire their own editor. Back in those days, the publishing houses hired the majority of professional editors, and they assigned them to their authors (the same way they assign designers and artists now).
However, as they started losing money, the publishing houses decided to shove their expenses onto the backs on authors. If you think the publishing houses are in trouble, consider the current state for professional editors. How many struggling authors can afford several hundred to several thousands per book? Not many, which is partially why we have so many failing books! They're poorly constructed, lack a professional quality, and hurt the author's reputation rather than helping them sell more books.
I feel sorry for most editors. They bend over backwards, trying to reach out to authors, often giving away hours and spending inordinate amounts of time 'marketing' their services rather than working on editing (which only raises the costs for everyone).
We have a very nice situation here at SOL, where anyone can find a decent collection of knowledgeable, non-professional editors, who get to be a part of a rich literary tradition and often go on to write themselves.
But, in the end, you get what you pay for. If you want to write professionally, then you've got to pay for the services that you require, and not expect everyone else to hand you the keys to your new career.