Why should people choose this instead of the competitor if it's a copy?

Because they found this one. It was marketed to them.

Just remember, Oreos were a ripoff of another popular cookie, Hydrox. Now, most people consider Hydrox to be off-brand Oreos, if they even know about them at all. Originality is overrated.

Not great advice in a world of ChatGPT at your fingertips.

You generate race-to-the-bottoms like the ChatPDF tools by leaning into easy to copy areas that online popularity highlights, rather than your gut feel around problems - how many of those existing ideas competing with ChatGPT for example are still online 3 months after many launched in Dec/Jan/Feb/March? Check theresanaiforthat, and even though they remove dead pages, under QA(or I think it's now a new catagory depending on the aggregator tool) you will see many dead ones, either outright no site any more or they do not work. Second issue: From my experience, it doesn't feel good to do this so you'll lose motivation...

An AI cannot charge money from customers. ChatGPT can't open a bank account or a Stripe account to receive payment from clients. If you actually sell something online instead of trying to make money with ads, you are going to be okay for a long time ahead.