If you look at the history of technological development, you'll see less of a need for high powered radio transmissions over time. Today, over 70% of everyone in America gets their TV via cable instead of through an antenna. This is likely to continue and is probably the case in most developed countries. Even those of us using satellite receivers don't require high powered signals. The programming is relayed via satellite to a central office then uplinked to the DirectTV or Dish Network. These aren't powerful signals, perhaps a kilowatt or two. The satellite then radiates signals downward. Even these signals are only a kilowatt or so.

Back in the early 1990s, I attended a seminar by an internal think tank at MCI. One of the speakers brought up an interesting point - the trend was that things which are wired were going wireless (e.g. cell phones) and things that were wireless were going wired (e.g. cable TV). Sure, there are millions of cell phones in use around the world but they radiate very low power levels. Even car radio stands a chance of being replaced over time by satellite signals. Early versions of satellite radio service are just now hitting the market.

If this trend is accurate, within 50 years we may not be using high powered radio/TV signals very much anymore.