I had a work colleague who referred their mother, a working photographer, to photograph their sports team. There was contention when the mother insisted on having her signature on the digital prints. It’s a position I empathize with but also question its practice in contemporary times.
Ensuring credit remains on an artwork could be resolved by embedding metadata or adding either a visible or camouflaged QR code. Other than copyright, an artist can choose to include their business address, website URL, keywords, etc in this format. But, I acknowledge the artist wouldn't be immediately visible to the viewer.
Some illustrators have adopted creative alternatives to identify their work and circumvent art thieves. A few of my favorite comic book cover artists have incorporated their brand logo in the image (the graphic on the character's clothing, store signage, etc). Some like to insert their brand mascots or self-portraits into crowd scenes. One can also incorporate their signature in a texture, ie a cat’s fur. It would be so boss if one could hide their signature with the anamorphosis art technique.