is watching news or a tv series with subtitles and audio of the language you are learning and effective way of learning a language
It’s a fun way to practice and pick up new vocabulary, and in that, it’s very useful and you should totally do it as part of language learning in general. But, if you are asking whether you can learn a language from scratch by watching subtitled content, I guess you could try, but I think it would not be the most effective way of going about it. (Yes, exposure is exposure and as long as you’re having fun engaging with the language etc. etc. etc. but there are other fun ways to learn way more efficiently.)
I sometimes watch and rewind and rewatch scenes – iOS apps have a quick 10 sec rewind button that can be very helpful for this – it’s fun to do, but I wouldn’t want it to be my primary source of language learning.
Subtitled programs CAN be great as part of a more comprehensive approach. If you’re learning in other ways and also watch movies and try to decipher what they’re saying based on the subtitles, that can be hugely useful and satisfying.
If you have problems hearing words out in your target language, then watching content with subtitles (in the target language) is a very good way to train your brain to recognize those words. It helped me with English/Japanese. But then again you need to watch quite a lot of subtitled content for it to have a considerate effect.