Tom Hardy’s portrayal of a younger Picard clone disproves the notion that anyone else could’ve been Picard.

I'm not disagreeing with you, of course a different actor is going to give a different delivery, but Patrick Stewart has no writing credits on TNG. Everyone's quoting lines he said from the show, but he didn't write them, he delivered them. While he had a great delivery, people are attributing the lines to him, but they aren't actually his. I don't really want to bring down the vibe, but it's worth pointing out that good writing is what made the show what it was more than only the actors. If the writers wrote vapid lines, and he recited them, would we be having this conversation at all?

Plus, in long-running series like these writers (implicitly and explicitly) write for the actor. It's a bit chicken and egg-y, but you absolutely cannot (honestly) pretend that another actor would have the same lines written for them.

I mean, in season one sure, but by the time you get to "there are four lights" Stewart and Picard really are inseparable.