As far as HAM and 'security' I'm going to hark back to my PP on 'perks and status' when it comes to expecting or demanding freebies.
It's the same thing.
Harry wants paid for security because he believes that is what he is due as a 'Son of the Monarch'. For him is it proof of his status-based-on-birth as, not simply a member of the RF, but specifically as Charles' son. I'd also throw in a bit of sibling envy too. He truly can't see the valid difference in what W&C and their children get for their security as the line of direct succession vs HAM and his children as, well, as the 'spare' & his family, and a non-working spare & wife as well. All he sees is that what W has, he should have also. I'm sure M abets him in this thinking, too.
For Meghan, once again it's the Hollywood mindset. The bigger the celebrity the better the security. And for true A-list Hollywood Elite, that security is usually paid for by others (a studio, a record company, a talent agency) who want their 'presence' and reputation to boost their own reputations and thus garner more A-list clients. Only B-listers (and lower) actually pay for their own security, usually to try to 'fake it til they make it' and get the 'perk' of paid for security. So for M, having 'paid for security' is to her a marker of status as an A-list celebrity. And we all know that she considers herself A-list, even if the wider world and those whose envy she covets, do not.
As far as I'm concerned their quest for what they believe is due them will never end be it freebies, paid for security, special treatment at schools, or to cut the line at Alton Towers.
How sad it is to be forever unhappy and angry like that. We all of us probably feel we 'deserve' more or 'better' than we have in one way or another. But we generally accept the truth of our lives and live happily with it. Too bad they can't do the same. I just hope they don't 'poison' their children's minds with their same mindset.