Barrier to entry, mostly. Implementation of most RF attacks historically required expensive SDR equipment and strong knowledge in a highly specialized domain.

Barrier to entry, mostly. Implementation of most RF attacks historically required expensive SDR equipment and strong knowledge in a highly specialized domain. Even many WiFi attacks which can be executed by off-the-shelf WiFi hardware require specialized driver/firmware hacking to execute, since most WiFi firmware isn't designed to send frames "out of turn" or with the wrong flags set. This is all evolving rapidly and I fully expect this to be one of the hottest topics in coming years. Flipper Zero is an obvious example of the change here - it was absolutely nothing new hardware or software wise, but providing easy access to standard BLE primitives and years-old sub-Ghz radio chipsets triggered a variety of meltdowns. More powerful SDRs and basic "building block" libraries for SDR are only becoming cheaper and more available every day.