I didn't believe it going in, long before I got into FWS. Violates rules C, E, N, and T of CENTS (and maybe S for most people). It's probably one of the first things relatively un or low-skilled people run to (along with copywriting) on the freelancing journey.
What changed my mind was encountering the total amount of local business that actually needed some service, either a website, some optimization, or some ads.
Need a plumber? Hey there's one locally with GREAT reviews but the number on his listing is Out of Service.
Need someone to handle your fence? There's 3 local contractors, two with bad reviews, but the third one's site doesn't have ANY pictures of their work.
Go to a business networking meetup and listen to the owners, almost everyone has a prospecting or secure source of leads problem, and a digital marketing company can solve that when executed well.
NOW, literally any jackass can reach out and close a "marketing deal" which plainly violates E in CENTS. What's also interesting is for the thousands of jackasses that try to do that, most get absolutely nowhere- and resign themselves back to their jobs.
You can be different, but would you be ready to differentiate yourself by putting in the (often painful) work of calling or walking into businesses to prospect, to spend countless hours learning the skills from the ground up, building and testing with your own and portfolio sites- and then risking it all in your first few high dollar deals (you'll have to learn sales btw) and praying all your work results in good outcomes and ROS for the client so you can get future work? It's not easy, but you'll get a crash course in a boatload of different business skills most product based entrepreneurs or even newly-started blue collar ones won't really face until they're well-established.
Either way you want to cut it, good luck. Surprisingly open but also surprisingly difficult- but once you get through the "hustle" and past the "hump"... well I hear it's like dream land, and even if you don't, you'll have met hundreds of business owners along the way.