A lot of it is actually data collection (mass spying and surveillance) being used to harvest and sell vast quantities of data... and that subsidizes the price of the device.
https://www.rtings.com/tv/learn/research/smart-tv-data-privacy
Basically, if we make the devices cheaper and spy on every customer, it becomes more profitable to sell at a loss to get more customers to spy on. If they could spy on your eating habbits with food, food prices would also come down.
Also, black Friday is bullshit. The prices usually get artificially inflated ahead of time and the good deals usually have very little units in stock. Door busters for the first five customers or some bullshit.
More importantly though, if it stops being so profitable to harvest data, prices will go up quite a bit on anything used to collect it.