Of course it is. Everyone’s mileage will vary. Not everyone is cut out to be CEO of a consulting firm. As a solo consultant, you’ll be hard pressed to charge more than they could get a FTE. As a firm, well, Deloitte, Cognizant, Pearsons, Booz Allen, all started as a consultancy or professional services spin off.
If you’re wondering how to be a consultant, you won’t get FAANG money. If you know how to be a consultant, it’s a matter of finding the right clientele and/or hiring a sales rep for their clientele.