Random Servo Movement with Arduino Uno
You call servoX.write() repeatedly, even when no button has changed. Each call turns off interrupts briefly while the servo value is being updated. This happens, maybe 40 times/sec and may be messing up the servo timing in some non-constant way. Try only calling the servoX.write() functions once, only when its button-state has settled into a new state.
Update:

could you provide an example please

  bool prevButton5 = LOW;            // one of these for each button
    :                                // outside of the loop() func.
    :

  if(digitalRead(5) != prevButton5){  // button changed?
    prevButton5 = !prevButton5;       // save new button state
    if(preButton5 == LOW){            // (your same code from here down)
      servo1.write(120);
      delay(20);
    }
    else{
      servo1.write(50);
      delay(20);
    }
  }


Make a boolean for each button.
Wrap each of your button segments as I did for button5. Notice that your code is now executed only if the associated button has changed, so you will have many fewer servoX.write() calls.

That isn't the totally best way to do it. I made it as straightforward as I could, even though the additional code gets replicated for every button. I'd probably write a single function that manages one button and one motor, and call that function for each button / motor pair.
I also ignored the concept of switch-bounce to keep the number of changes low, but you should look it up and consider it. Switch-bounce is apparent bouncing of the switch contacts for a few milli-seconds during the change from open to closed or vice-versa, which leads to several make-break-make.....-make cycles (or the reverse) when you push or release the button. I'd probably make (or search for) a button debounce function and call it for the particular button I'm testing if I see that button has changed.
First try the &quot;rude and crude&quot; fix I suggested and get that working. Then if you're interested, try making one or more of the refinements.
Update:
the servos still jitter and twitch esspecailly when
I move the whole arduino and wires around.

That suggests either or both of

cross-talk;
the plug wires' connections being less than solid, especially when the wires move.

Try:

laying out the servo cables to keep them away from each other as much as possible;
wiring only a few of the servos, and in different combinations;
also try commenting out the code - or not - for those servos you disconnected in the previous step.

If it turns out to be the plug-in wires and if this project is intended to actually be used for something, I'd suggest using a screw-terminal shield on your Uno to attach the servo wires more securely.