Until everyone understands every language out there, I guess. Dubs and subs have both been around for a long time, though some countries tend to prefer one over the other. Are you going to watch an Australian movie on a German tv channel? Be prepared for your favorite actors to speak German. 
If you watch it on a Dutch channel, though, you will get the original audio with Dutch subtitles. We only have dubs for some children’s shows.
Luckily, nowadays, sites like ■■■■■■■ let us choose whether we want the original audio or dubs and in which language we want our subtitles, although on Viki, the dubbed versions (check the Coming Soon) are presented as separate shows.
Dubs can be beneficial for some so I’m not saying they shouldn’t exist but they should never ever be the only option. Whether done by humans or machines, they always make the show seem unnatural. Apart from that, they deprive us from hearing the original language.
@angelight313_941
Take a look at your NF profile settings. You can set preferences for your languages for both audio and subtitles. Also, you can nowadays “browse by language.” If you put “original language: Japanese” and then start watching one of the results, you get the Japanese-spoken version without subtitles. All you have to do then is turn on the English or Spanish subtitles.
I watch everything in the original language, but the language of my subtitles depends. NF remembers it, though.