It's not the only way. In the article it says that Netflix already has 30% of streaming content captioned, with plans to expand that to 80% by the end of the year.
I bought my mother a third-party device for her television so she could stream Netflix last Christmas only to find out that Closed Captioning wasn't supported. It was pretty depressing - she couldn't use it at all because she is hearing impaired.
There's a reason why there are laws in place for compliance - often times good business strategy and "accessibility for all" don't align.