I have a D5100 paired with a 35mm 1.8 and another 28-75mm 2.8 with no stabilization. I am stating to get somewhat decent at the basics but still struggle sometimes, but recently I got my hands on a Z5 and all the shots that I was normally struggling with were getting perfect with so much less effort.

So my question kinda is that by keeping the 5100 am I holding by developing back ? Instead of spending time trying to counter my struggles with trying to focus moving objects, fighting the autofocus in low light and lack of stabilization, I could focus more of getting the shot that I want, so is this a case where my old camera is holding me back or just skill issue ?