Not necessarily.

In theory if the price increases were at a slower rate than general inflation, the effective cost goes down. Additionally, they could add additional content, thus increasing the value of the provided service, at a rate greater than price increases.

In practice, yes Netflix and other streaming services have been becoming less valuable as time goes on because while costs have been driven up, available content has generally stagnated or even decreased as more media companies decide to open their own platform, pulling their content from the competition and diluting streaming value across the board.