Yes, I did it for about 10 years. Attracting clients is the easy bit. Attracting good clients is not. I gave up in the end because it was so hard to get people to pay a reasonable hourly rate, and on time. And...
Another problem is that small businesses need a book-keeper because they don't know how to do it themselves. This means that you usually arrive to find a monumental cock-up that you have to sort out, and then they argue disagree with you when you tell them that things need to be done properly differently from now on. Because they think they know better than you despite the easily proven fact that they know sod all.
Another problem is that you usually either have to work at their premises, or keep going there and back to collect/drop stuff off. Or spend hours trying to get to grips with a cheap and crap online accounts package that they have already set up wrong (GIGO). And they always leave it until the absolute last minute before their tax is due before calling you in.
Another problem is that they will probably may try to get you to fiddle their VAT for them.
Another problem is that you need to have a good few years of experience in a very wide range of business types and industries. Every business is operated entirely different from every other and you need to be able to adapt really quickly.
Finding work is easy - as long as you're happy working for minimum wage (or less) and working through the night because the numpty client left things to the last minute.
Decent clients who value your work and will pay a decent rate are much harder to find.
It's also not just book-keeping that small firms want. They want someone who can do their payroll (properly), VAT returns, CIS returns, etc. Does your experience extend to all that? They don't want different people doing different things. They don't know it, but most want a management accountant rather than a book-keeper. It's a hard job getting them to understand that.