I used to work for a small web agency. Clients would buy websites all the time without having a clue what the content was going to be. Occasionally I'd say "We can't start work until you provide us with content." Most times it was a deal killer: the client wouldn't sign the contract unless they saw the design first. In other cases, the client would promise to find content, but never deliver. I can't tell you how many blank websites we billed out after waiting for months with no content.

Because clients dragged their feet on getting us content, most of our sites had to use placeholder texts. The client would delay content until the last minute. Then, as always, we'd get some shitty word document with content that didn't fit into our design. Text was crammed into places it didn't belong. Feature boxes were created for content that didn't exist. A design disaster. But clients loved it. And it got contracts signed.

If you're a freelance designer, team up with a good copywriter. 10% of the time, the client will agree to have their site written by a professional, you'll get content on time, and everyone will be happy. The other 90% of the time, the client will try to save money by writing it themselves. They will either write an indecipherable crap-pile, or absolutely nothing. These are the clients that pay your salary. And that's why placeholder text will always exist.