The market is what the market is. While it may not be "socially equitable", senior developers are currently the perfect combination of high-demand and low-supply.
It is not "entitled" to demand to be paid the maximum value the market will bear for your skills. It is stupid to do otherwise.
You basically (literally) said exactly that. "Entitlement" is not a personality trait, "acting entitled" is, and even then it's only a negative if you aren't entitled to whatever you're "acting entitled" about.
"Entitlement" is literally nothing more than having the "right to something." And as a human, you are absolutely entitled to being paid exactly what you are worth.
> you are absolutely entitled to being paid exactly what you are worth.
Sure, whatever. But what you're not entitled to is being worth something in the first place.
If you can't recognize your own fortune in enjoying and being passionate about something which, as a side effect, makes you valuable to companies, I don't really see this discussion going anywhere from here.
It is not "entitled" to demand to be paid the maximum value the market will bear for your skills. It is stupid to do otherwise.