Everything (save for artificial intervention) is getting cheaper, starting from commodities. This is true when measured with a constantly shrinking measuring stick in fiat.
Now couple with technological progress and you will see why the price of un/low regulated products keeps dropping. 
Why aren’t my Mac upgrades cheaper than before? Why aren’t iPhones getting cheaper? Why aren’t my cars getting cheaper? Like televisions.
All of the above: you are measuring in fiat (imagine measuring your nephew’s growth with a height measuring stick that changes its length materially in months).
Macs & iPhones: you are conflating luxury goods with cost of unit compute power.
Cars: regulations. See https://www.roadandtrack.com/reviews/a45752401/toyotas-10000-future-pickup-truck-is-basic-transportation-perfection/
