What is the goal of the watermark?
If it is to prevent people from stealing the photo and claiming it as their own, then no. It won't work. It's easy to remove a watermark. Even I could do it.
If it is to advertise your product/site/whatever, then it's useful to have a faint web address or easily searchable name. That way if someone borrows the image for social media, it acts as advertizement. But, I personally feel it's better if done tactfully with a faded watermark that looks beautiful. So often, I see images with black or white text layered on them, which I think looks pretty unprofessional. Even something as simple as the way the photographer made the text wavy for watermark looks good to me:
https://www.blipfoto.com/entry/2655451446832530430
As for the first problem, this is a bigger area. In most of the West (canada, UK, US, much of Europe, and possibly elsewhere) the ownership of the photo belongs to the person who presses the shutter. This ownership is nontransferable (in most places - it's going to depend on where you live so don't trust what someone says on the internet, find your
local photography association or ask a lawyer for your local laws). Protecting these rights isn't easy. Once you've published a photo, it's out there for anyone to see and with today's technology, steel. Once you upload a photo, you've shared the use-rights with the publisher of that site. It gets very complicated, very quickly. Basically, it's not worth the money or effort to protect the photographer's rights once the image is out there.
There are a few things we can do before we publish the photo to reduce theft.
1. Don't publish: If I'm hoping to write an article or book on a subject in the future, I keep the best images on my computer (and backup drive). I publish my B-role (second-best images) or deliberately poorly edited images on social media. That way if I sell an article to a
magazine, I can promise all-new content.
2. Small and poor resolution: This is something I'm trying to do more. I scale down the image to be 700pixels on the long edge before uploading it to somewhere like permies. That way the image is of less use for people who want to use it.
3. Watermarks: again, this is easy to remove, but most people don't bother when sharing on social media. It becomes free advertising.