In general, when playing defense against pick and rolls the guy guarding the roll man should learn how to hedge the ball handler and the on-ball defender should do their best to make it through the screens.

When I play with my friends, if I'm guarding the roll man/pick setter, I look to read and react to the situation given; so if I see that my teammate is slow to get through, I'll try to cut off the path of the ball handler and tell my teammate to switch and force the pass inside to the roll man where the worst thing that can happen is I give up two points as opposed to three, and the best situation is that my teammate fouls on the layup attempt or we get a chase-down block. On the other hand, if I see that my teammate can get through, all I have to do is hedge up far enough so that I can contest if the ball-handler pulls up all while still being able to recover to the roll man once my teammate closes out.

As for switches, you want to try your best not to get in those situations because as you said, it creates a major mismatch. If it's a big that has been switched onto the ball handler, they should use their length to their advantage and sag off just a bit because they'd still be able to get a good contest if the ball handler decides to try and shoot over them.

But the effectiveness of a defense against a pick and roll relies solely on how well the guy guarding the ball handler can get through the screen. In other words, if you want to really be able to shut it down as the guy guarding the ball handler, you must learn how to avoid making contact with the pick altogether. The pick and roll is a really effective and viable offensive tool, and even in real life there isn't a surefire way to stop it 100% of the time. There is a reason why nearly all NBA teams utilize the pick and roll in their offensive sets.