That’s the interesting part with AI: the most problematic aspects of IP are retained while the defensible aspects are eroded. Normal artists and creatives can do nothing about their work being stolen, while big corporations profit from it and even pretend to have ownership over the new output. It reminds me of this quote about conservatism.

Conservatism consists of exactly one proposition, to wit: There must be in-groups whom the law protects but does not bind, alongside out-groups whom the law binds but does not protect.

Property in general is no more real. Your ability to "own" something is dependent on other people's acknowledgement of that ownership and the means available to you to prevent others from taking it. In modern society, the state putting in some effort at threatening consequences for what it considers illegitimate seizure of what it acknowledges as your property, is part of those means for most people, but it's still ultimately something that only exists in people's heads. Nevertheless, if I were to break into your home and empty it out, I doubt you would just shrug and think "Well, property isn't real, anyway".

There are a lot of things that aren't really "real"; states, laws, money etc., so it's pretty pointless to try to delegitimise something by insisting it doesn't fall under some definition of "real". It's much more useful to think in terms of what the merits and demerits are of keeping up the illusion. There are certainly a lot of problems with intellectual property, some with the implementation, some more fundamental. At the same time, under the current economic system it's often the only thing available to creators that allows them to make a living off their work. So if you're just going to crow "IP bad" without offering alternatives to either IP or the economic system, it's just going to look like you mean harm towards those creators.

But there's something more fundamental than IP that's the problem here. Obviously, NJB doesn't have the exclusive rights over having an opinion on Toronto's line 5, and nobody should be restricted in making their own video in which they express their own opinion about line 5. But that's not what's happening here; the "creators" of this slop don't have an opinion on line 5, they've probably never even been in Canada. It only exists because NJB is a decently popular YouTube channel and it's very low-cost to make, in part because of AI, but also because they have NJB's video to rip off. In other words, they're trying to profit off somebody else's labour while potentially reducing how much the original creator is rewarded for their labour. That's a problem regardless of whether you believe IP to be the way to deal with this or not.