A combination of the above.
In the bad old days when we had two or three flash fill explosions there were unrestricted fast fills operated by anybody, irrespective of whether they were 3000 or 4500psi, there was a lot of high pressure air going in fast and getting hot, add those factors to contamination and an innocent guy was the victim of a flash fill explosion and burns
The situation is now very different. Even if you see uncontrolled fill stations the fill stations you are likely to find at any good site will be restricted and you are less likely to feel bottles get hot when topping up. If you are filling from empty then pause to fill in 2 or 3 goes and your cylinder should ideally only get a bit warmer (it's also counter productive to fast fill and end up with hot air, as it will soon cool down, contract and you end up with less air)
For a site to run 4500psi fill stations they have the extra expense and risks of higher pressure cylinders, higher capability compressor and the knock on effects of risk assessments and insurance premiums of 50% higher pressure
They are more likely to run a 3000psi site system and bring in HPAC to supply 4500psi for events
To give players a consistent 3000psi or 4500psi fill, rather than run compressors all day, a site will typically have a series of holding tanks at a higher pressure feeding the fill stations, and the compressor topping up the main tanks
The guns that people use are more efficient and game lengths are short enough that players shouldn't be running out of air whether they have 3000 or 4500psi
(Even at walkons, though sites may have mobile scuba cylinders that can be taken out to more remote game zones, or have an in field fill station, allowing groups to head out for a few games)
A site will gain more from giving players easy access to regular fills by providing extra fill stations for less queueing then by giving a more expensive 4500 fill system
Note that it's one of my counter arguments when new players used to get told that they must start with a 4500psi cylinder - where are they going to get the extra fill to justify the extra £100 expense, that they could spend on other gear or paint
In the bad old days when we had two or three flash fill explosions there were unrestricted fast fills operated by anybody, irrespective of whether they were 3000 or 4500psi, there was a lot of high pressure air going in fast and getting hot, add those factors to contamination and an innocent guy was the victim of a flash fill explosion and burns
The situation is now very different. Even if you see uncontrolled fill stations the fill stations you are likely to find at any good site will be restricted and you are less likely to feel bottles get hot when topping up. If you are filling from empty then pause to fill in 2 or 3 goes and your cylinder should ideally only get a bit warmer (it's also counter productive to fast fill and end up with hot air, as it will soon cool down, contract and you end up with less air)
For a site to run 4500psi fill stations they have the extra expense and risks of higher pressure cylinders, higher capability compressor and the knock on effects of risk assessments and insurance premiums of 50% higher pressure
They are more likely to run a 3000psi site system and bring in HPAC to supply 4500psi for events
To give players a consistent 3000psi or 4500psi fill, rather than run compressors all day, a site will typically have a series of holding tanks at a higher pressure feeding the fill stations, and the compressor topping up the main tanks
The guns that people use are more efficient and game lengths are short enough that players shouldn't be running out of air whether they have 3000 or 4500psi
(Even at walkons, though sites may have mobile scuba cylinders that can be taken out to more remote game zones, or have an in field fill station, allowing groups to head out for a few games)
A site will gain more from giving players easy access to regular fills by providing extra fill stations for less queueing then by giving a more expensive 4500 fill system
Note that it's one of my counter arguments when new players used to get told that they must start with a 4500psi cylinder - where are they going to get the extra fill to justify the extra £100 expense, that they could spend on other gear or paint