Thanks Lebasi. That is a good point. I have thought of the dumb trainer. I’ve also thought of one day taking the power meter pedals to somewhere that has a Kickr Bike or something similar and testing them on there. That would sort of put an end to this because if the Kickr Bike was producing wattage similar to the power meter pedals then I would know they are accurate on a few different levels.
I’ve also thought, and yes this is a little weird, but to ask a fellow cyclist (no idea who), that knows all too well what 200 watts feels like, to my home to try the pedals and spin bike themselves. If they say the spin bike at 200 watts feels like 200 watts then I would know it is me and nothing with the bike or the pedals.
All this would probably be doable and done by now if it weren’t for this dumb Pandemic. I’m still not doing group rides until I can get the vaccine and I really don’t leave the house except for solo rides and mostly essentials. Does Cheeseburger Friday count as an essential? 
Anyway, that is interesting to hear about your Brother. I could very well be in the same camp as him, but I’m still not convinced until I can get some real data behind it, which just might have to wait.