There is no power difference between using a mtb shoe and pedal vs a road bike shoe and pedal as long as your not racing.
I agree I think most racers would want a road pedal and shoes while racing. But what really surprised me one day on a ride. I rode with a group of racers up a mountain road. OK, I'm the biggest guy at 230 pounds riding with some smaller guys of 150'ish. 6 of us!
One guy is a well known winning local racer. Older now but won masters, everything, great guy too!
We rode about 15 miles to get to the mountain road (Glendora Mtn Rd). 8 mile climb with 2300 ft, I believe 6% average. The champ rolled away from most of us. One guy about 200 faded half way up. 3/4 of the way up, I was going back and forth with the other guys.
I ended up dropping the guys and got to the top second rider, only to the champ. He asked if I raced. Nope, I just like to ride at my schedule and for fun. He said at my size, climbing like that, I should race. Nah, I'm just a fun recreational ride, heck, I even use MTB shoes on my roadie.
Surprisingly, he lifted his foot and asked,"what does this look like? I use MTB shoes as well!".
Heck the dude won crits, road races, the works. Using MTB shoes!
I used to wonder if I was missing something but once he showed me his shoes, I never looked back and have been using MTB shoes on my roadie since 1996.
But I agree with Froze overall. I have had people tell me I need lighter shoes, wheels, need to slam my stem but on rides, they can't keep up or have to suck my wheel for the most part. Now, put me in training mode, drop 50 pounds and actually train as I have a few times leading up to timed events, the weight of a wheel, shoe, or heavy sun screen won't slow me down a bit.
People want to buy speed, that is cool if you have the money. But as many have said, I think it's just the cool factor!
