I feel like it's more that the tech industry can't think of ways to keep innovating the smartphone to justify continually charging more for them. Like how TV's have effectively plateaued after 3D TV's didn't take off.
The "folding smartphones" being the next big thing hasn't managed to catch on as they've hoped.
The AI assistance boxes that all the media outlets were hyping up was just scam product.
That said Samsung and Apple keep charging more for minimal speed improvements at the top end of the market and they keep selling.
But, it's not like people have stopped using TVs either, it's just that TV prices keep going down rather than up because there has been no innovation in the market.