Why is the LEGO IR Receiver V2 not widely produced? Or are they?
No, the V2 receiver isn't available in any new products. It's only available in the sets you mentioned.

The most likely reason it's not available in new products is that the production cost would be higher and hence also the set price which would make the sets less attractive for most lego customers.

Also there is an issue with the V2 receivers when having more than one M-motor on one output port while this is not problematic for the V1 receivers.
It has to do with the high capacitance of the M-motors (for noise reduction) that tricks the V2 receivers into believing the motors draw too much current.

On the box of the 42030 set, V2 receivers are depicted, while the set itself only contains V1 receivers. I contacted lego support about this, they said that actual V2 receivers would likely cause the motors to possibly damage the set and that late in the design process they switched back to V1 receivers without updating the box art.

Performance wise, a good alternative for the V2 receiver is an sbrick.