I did extensive research on this in undergrad and always like to talk and share experiences with others. I happen to live in a control state as well (PA) but I think a lot of people misconstrue the differences between the two, either due to ideology or an anecdote, that misrepresents the difference between the two. FWIW, I don't advocate for either and I think making generalizations about the two don't help.

You can have both state run stores or private stores be more expensive or less expensive depending on the brand. Brand A might be cheaper in a state store while Brand B is cheaper in a private store but more expensive in the state store. Taxes in private states, like in WA can make private states look worse, but when compared to California or Delaware, private run stores can be a dream.

Everyone thinks a private state may be a utopia when it comes to customer service, but not every private state has a K&L. The large proportion of liquor stores can be run by shitty people, sometimes worse than a disinterested state employee, and could even charge ridiculous prices simply because they have a rent monopoly over a certain location. Some state run stores make sure there is price parity across the entire state. Also, Pappy won't get marked up to $1000 in a state store, but you are destined to deal with grift, perseverance or a lottery. Sometimes having those connections in private store is all you need to get some sweet Pappy at MSRP.

When it comes to selection, you do have the options to have your guy get something for you, but state stores also have that option too. PA has public board meetings that anyone can attend (no one does) and make recommendations about what they would like to see in stores. If a case for profitability can be made, (aka people buy it) then the state would try and stock it.

There is some democratic leeway in deciding what state stores can do, and in a way that is nice. /r/PLCB was proud of pushing product recommendations that are now on the shelf and on the website that wouldn't' have been there without all of us rallying together and making the recommendations in person at the board meetings. You can also special order from distributors. However, there are products we just won't ever be able to get.

And there in lies the rub: the fault between private and state sellers is small when it comes to the real villains of the three tier alcohol system - distributors.

Distributors, IMO, are the ones who dictate allocations and price. The reason why you can't get Weller 12 as easily as Texas is not because of your shitty, po'dunk town state run store, but because Buffalo Trace insisted that certain distributors allocate their Weller 12 to that part of the state. This is why, even in super cheap states, you can find a bottle of something that is way out of a price range compared to what you might even find in a control state. Allocations and distributors are region based, as dictated by the 21st amendment. Control states are known for getting "distributor" gifts and such, just to push some shitty product that producer insisted they push. Or why you can't get your favorite bourbon into a state because the distributor thinks "there is no market for it." (Aka "if you want more pappy, buy more fireball")

In conclusion, before trying to put the blame on private or control states, take a bit to understand the three tier system of distribution, as mandated by federal law, and then you will realize why liquor price and distribution in this country sucks from state to state.