It's only growing if that hardware is selling to new gamers and not existing gamers upgrading. Is Switch selling to 3DS owners? Is PS4 selling to PS3 owners? Well, it depends how you measure growth. Financially, more dollars spent, it's likely growing, but I think that generally true every year.
The market goes through cycles, rising and falling because we have young new gamers entering the market and older gamers losing interest in games and falling out of the market.
https://www.statista.com/statistics/276768/global-unit-sales-of-video-game-consoles/
Assuming the chart is accurate, we were seeing a steady decline year over year for console sales going back to 2008. PS4 sales for 2017 nearly match all console sales combined in 2016. Even in 2013 with the release of the PS4 and X1, there was still a reduction in year over year sales, and then 2014 saw another reduction in sales. 2017 is like the first time in many years we will have seen an increase in year over year sales, and could very well be the best year for console sales of the current generation. I think that is a good sign.