So we've had flat beds on planes for a while now. So why don't we have beds or loungers where people can nap while they wait for their flights? When I have a long layover in between flights, the thing I'd like to do most is (aside from getting a massage) sleep.
Some lounges have sleeping areas, such as the Qatar 1st class lounge in Doha, where they have individual small rooms which resemble a small hotel room with a bed, bathroom, desk, TV but even in regular lounges, it would require just buying some day beds and setting aside a section of the lounge, pretty easy to implement. This is something I'd like to see airlines implement.
As an aside, the best perk (aside from the room at in Doha) in a lounge for me was the free masseuse at the Phuket Priority Pass lounge. You should tip the masseuse a bit but even ) with the small tip (I guess equivalent to a $1 for a 15 minute massage, it was great. Now the Centurion Lounge in Miami has 15 minute free massages.