Usually it means you have to manage people but you have no real input on their career trajectory, and in the worst case, if they need to be fired you do not have the power to do so.
I would suggest maybe step back and think about a point in your career where you really felt challenged and inspired. I've definitely had periods where I felt similar, but was generally because I was just bored and didn't feel any connection to the work I was doing. So many of us attach so much of our identities to the work we do. And if the work we do isn't meaningful then we end up in thought processes like yours.
The fact that you are really looking inward and thinking about this is super positive by the way, because without that things will never change.
Think about what it is you really want to achieve and find a job that gives you a sense of ownership and pride.
I did this back in 2009 and dropped a wad of cash on a Mac Pro tower. Thing is a frickin' champ. Upgraded it to 12GB of RAM and a nice SSD for the OS drive and never looked back. Turns out 4 Nehalem cores at 2.66GHz will last you quite a while if you don't do video editing work or play the latest games at full resolution.