This is pretty much what OpenAI tried to do with Scarlett Johansson (or more specifically, her voice) before they got hit with a C&D. Of course, this was after they had already tried to work with her directly so the intent was pretty obvious in that scenario.

I'm sure they did this for a james bond game once, they couldn't get pierce brosnans likeness so they used his stunt double, and with it being the PS1 era the lower res graphics helped with the likeness

The operable word here is "likeness". It doesn't have to be them, specifically. But if reasonable people look at it and say, "Yeah, that's [person]." then that also counts.

Just say you're AI. It's free then.

As a disclaimer: I'm not an expert (or a lawyer) on the subject, but am interested in it and have done quite a bit of hobbiest research.

From my understanding, you can, but have to be able to defend your claim in court. For example, there can't be significant evidence that you were previously looking at the celebrity, and you obviously can't use features specific to the given celebrity. That said, its going to be very easy to prove if you are the lookalike or are working directly with them.

An ad campaign hired people with the same name as famous people to get endowments for them and use their name making it look like it was the famous counterpart the one who gave them

You know that everyone's likeness is usually protected under (us) state law. it's technically called the right of publicity; so usually you can't use that other person's face either without their consent.

You really wouldn't even need to do that. Just make a slight change that differentiates your character from the celebrity, give them a unique name that has nothing to do with the celebrity's name, and you can claim this is a unique character that should not be associated with celebrity.

There are a few things that need to be clarified, because they're all fairly distinct even though they might seem to be doing similar things:

• Copyright: protects the reproducibility of some work. Objective: a time-limited monopoly for the owner to control copies

• Trademark: protects the authenticity of a vendor. Objective: elimination of marketplace confusion; vendors are judged on their merits

• Patent: promotes disclosure of innovations and protects the use or application of an invention. Objective: a time-limited monopoly for the owner to control uses, but must disclose the secrets for how to build it

• Defamation: (USA specific) protects against provably false statements published about someone. Objective: elimination of lies from the marketplace of ideas, but does not affect opinions or public mores

• Right of publicity: protects personal marketability and opportunities. Objective: elimination of labor marketplace confusion; person will be judged on their merits

There are two things which can cut against almost all of these: fair use and parody. Fair use arises commonly in copyright but the logic is the same: in order to discuss something, the thing must be identified. The marketplace of ideas cannot exist if nobody was allowed to screengrab a TERF's wizard movie or mention why they don't like a certain cola company. The key is to be minimize the incursion to what is absolutely needed. For example, someone organizing a boycott can indeed use a brand's logo to refer to that brand.

As for parody, it goes a bit further and will (for comedy or sarcastic intention) assert that the statement is true or the work is authentic. This too is allowed, because -- at least in the USA -- poking fun at things is a valid (and human) way of discussing things that would otherwise be difficult to say. How it relates to defamation, trademarks, and right of publicity is that a reasonable viewer of the parody must be able to determine that yes, it's a joke and it's not actually making that particular point but rather a different one. This is akin to someone nodding their head to say yes but verbally saying "no": there are enough mixed signals that nobody would take the assertions seriously.

So would someone's face be "locked out of the arts"? No, not by copyright. But under right of publicity, they could have a claim if the depiction could potentially be confusing. Fortunately, this generally can be cleared up by explicitly identifying who the depicted face belongs to. And also to never try to sell or distribute artwork that rides on that person's coat-tails.