Failing to learn scalable marketing will ruin your freelance business.
You have no control over the frequency and quality of client inquiries through pure word of mouth marketing.
This approach takes years to generate consistent inquiries.
If the market is in a slump, word-of-mouth can fail completely.
Most devs try to only sharpen their technical skills and hope to avoid the new marketing and sales skills they should learn.
Instead, they buy into the fairy tale of word-of-mouth.