If jamming is so good, why have radars at all? I don't think jamming is really that effective on a large scale.

Anti-chaff and such measures have been gradually implemented a long time ago, since it is literally WWII technology.

If jamming was super good, why are suicide drones such a big threat? They would be unable to get close because you'd have a jamming field around your units. Yet all it does is shorten the range.