Basically, what this all boils down to is if you really need a compressor or just want one.
What I mean by that is, as I have already said, I shoot a relatively low powered .177 airgun for pesting in my backyard. So I take relatively few shots over a few days or weeks at times. The airgun is VERY efficient, such that when I have shot about 3 mags/30 rounds, it only takes me 30+/- pumps to bring the airgun back up to full capacity at 3000psi.
The only time I shoot a LOT of pellets in a single session (more than one 10 round mag) is when I start to miss a lot and have to try and figure out why. Even then, I don't shoot the gun (regulated) past 2500psi to keep the test consistent. And most of the time, I can attribute my missing to the person pulling the trigger... (sheepish grin)
However, the scope I am using is also prone to shift POA/POI from time to time and a new tin of pellets can also make a difference. See my sig...
Now, if you shoot a lot more than that or are using a higher caliber gun, especially something higher than a .22, then you start to get into the realm of where a compressor might be something you should consider.
If you like to shoot LOTS of rounds in a single session, even with an efficient .177 or .22, then you may want to consider a compressor.
There is one comment from beerthief who says he is 77 and hand pumping is not a problem. I am 63 and not in great shape, and hand pumping is not a problem.
Another thing I wanted to mention. I try to only pump when the dew point is relatively low. Right now, the dew point/relative humidity is very low (DP 33, RH 73, temp 46F) and I actually am running fans in my windows constantly. When the temps and dew point start to rise enough to run the A/C, I will only pump when the air is relatively dry inside my house. I NEVER pump outside during the summer here in Alabama. The humidity is just too high.
Anyway, IF you NEED a compressor because you shoot enough or have higher caliber airguns that use a lot more air, then go for it!
BUT, there are a lot of us who shoot lower powered low caliber airguns who get along just fine without spending all that money on tanks, compressors, etc.
And apparently most of us are older... maybe wiser. (grin)
p.s. Don't believe the marketing that you NEED more than you are satisfied with.