Open circuit/ short circuit at microwave frquencies

I am a novice in RF/microwave. Just learning it for the fun of it. I am currently reading a book called Microwave Transistor Amplifiers by Gonzalez. In the book he states that it is hard to find z,y,h, ABCD parameters for a two-port network because the open/short circuit conditions are hard to implement at high frequencies over broadband. I tried to think about it and came up with the following explanation. Just wanted to confirm if my thinking is correct.

It is hard to implement this because at high frequencies in a short circuit, the voltages would be different at different points along the length of the wire. This means in some ways there is a potential difference between two points along the wire which goes against the concept of a short. Is this logic correct?

I couldnt think of a satisfactory explanation for the open circuit case. Could someone help me here?

Regards,

Just about any discrete connection has some stray inductance and capacitance. Shorted coax has inductance of the shorting connection, open end coax has stray capacitance at opening.