The benefits of miniaturized solid state technology, more efficient batteries and SATCOM replacing much of the HF long over the horizon communication makes it so.A ROMAD is great for helping the JTAC, but in reality is not really needed. Any good JTAC worth his salt really does not need one.
The current ground environment not being armor, artillery, or mechanized infantry sort of does put much more reliance on hoofing and man packing (ruck marching) the communications around too. If you look at the Koran War and Southeast Asia conflict many pictures of jeeps with large radio suite in the back. Not saying radio were not rucked marched in with the rest of the infantry in those days, just saying equipment and Air Force aircraft support to the ground fight tactics have changed much since then and now.
Radio repair and maintenance has changed some as result of miniturized solid state circuitry technology too.