A few things to consider: Pressure and flow are inverse to each other; as one goes up, the other goes down. Also, pressure is like energy, it cannot be created nor destroyed, only converted. If your home water pressure is 65 psi, that is the maximum pressure you will ever obtain; to be otherwise is physically impossible.
Think about a garden hose. Unravel it, put a nozzle on, and open the spigot. For a few seconds, the hose is filling (there is flow) so the hose doesn't charge immediately. Once there is no place for the flow to go, the hose charges to the maximum pressure as supplied by the water company. The nozzle is the restriction; everything upstream is pressurized, nothing on the downstream. Squeeze the nozzle and water comes out. The pressure inside the hose drops and flow is increased. The restriction is still the nozzle and everything upstream is of higher pressure than what is coming out of the nozzle. When you feed those tomatoes growing in the corner, you are increasing the velocity of the water as it exits the nozzle because you are increasing the pressure differential on both sides of the restriction. There is still pressure upstream of the nozzle and none downstream. At no point will the pressure inside the hose ever exceed the supply pressure.
Getting back to our RO units. The 1/4 inch hose where it meets the spigot is the restriction. When you open your feed valve, you are supplying water to the filter. Because there is flow, there has to be a pressure drop. If you were to shut off all of your filter outputs, the pressure will eventually reach 65psi. The same instant that you crack open the output valve, the pressure is going to drop. We can maximize the pressure to 65psi inside the unit, but we make no water. As I stated before, every RO unit that I know of contains a flow restriction device inside the waste water line which also happens to be the most downstream component in your RO filter assy. This restriction causes the pressure inside the filter to increase (pressure is always created upstream of the restriction.) In your statement above, you are confusing flow rate with velocity. 100gpm exiting a 6 inch pipe isn't going to water those tomatoes in the corner. 100gpm coming out of a 1/4 inch tube, you can water your neighbors tomatoes as well.
This is much easier to explain in person. I only hope I don't confuse anyone.