I think Harry was bitter about many aspects of royal life in Britain long before he met Meghan (in 2008 he said in a public interview that he didn't like England). And his dislike of the press has been obvious for ages (and I do understand this).
I think he was ripe for somebody to come along and disillusion him even further. It's just a pity, for his sake, that the life he's escaped to is just as limiting, in its way, as his royal life.
The picture a PP painted of the private life he could have been living on an estate in southern Africa is very vivid and it really rings true that that would have been him living his best life.
I don't think it's all on Meghan that he's not living that life. He is an adult with agency and he's choosing to let her call the shots.
[Edit: added missing word]