I've tried to improve my French via Netflix and it's useless. Netflix subtitles are often just the English subtitles independently translated. Even for original French content you are not guaranteed to get correct subtitles.
I doubt they were considering language learning when subtitling, unfortunately.
I do agree with your sentiment that the web at large unfortunately still isn't great in terms of accessibility :/
Except for some short phrases, the subtitles were very close to what was spoken in rapid-fire Spanish.
The problem with “La casa de papel” is that is a serious multi-layered plot with complex characters that requires a lot of thinking.
“Club de Cuervos” is entertaining and no thinking compared to it. However, the constant use of Güey or Wey and “no manches” may annoy you.
COVID has given me a reason to watch more content. I've found myself watching some fabulous output from Korea, Japan and elsewhere on Netflix.
But the subtitling on Netflix is just abysmal. I mean seriously, we're talking about schoolboy fundamentals here. White text on white/bright background ? Yup, Netflix does it, not just occasionally but A LOT. Subtitles bouncing around the screen during the course of the same film/episode (i.e. jumping between top and bottom of screen). Yup, Netflix does it, again not just occasionally but A LOT.
Honestly, makes me feel sad for those hearing impaired people who actually rely on subtitles.