I'm not going to get into to the "gain wars" (yes, text bok, real-world you can have just one "good" (high gain) antenna, and it will work just fine for send and receive) - but your answer prompts the obvious question: What about lasers? Turns out, before optical lasers there were masers - microwave lasers, bit they were (are?) very limited power:

https://www.scientificamerican.com/article/first-practical-m...