Well, yes and no.
Yes because you absolutely can steal another person’s ideas by lifting them off of one page and putting them on your own. No, because while taking someone’s work and passing it off as yours is wrong, we are all constantly influenced by the work being done by others.
Many fans refer to media clearly influenced by preexisting works as “filing off the serial numbers” and Heinlein even referenced this in one of his books. Even scientists and other academics borrow ideas and steer their research in new ideas based on the work of others. You can find a list of these influences in the references section of academic publications. Creatives do the same things when they get asked who their influences are. In fact, it’s practically required for authors to list comparable works when they are trying to get published.
So creators worrying about “stealing” someone else’s idea should in fact feel free to create whatever they want. Maybe you recently read a book or watched a movie that got you thinking about a certain type of setting or plot and you would like to try your hand at something similar. Are you worried that you are just stealing the premise of that media? Don’t be!
Sure, someone might have made something similar already, but as long as you make it different you are making it your own. In