Remember that Netflix only needs to keep you subscribing. They don't want to spend more than they have to. If you were canceling your subscription, they'd change something. If not, they're perfectly happy with your money.

They do a lot of subtitles -- as many as a dozen, for each property. And they have a lot of content. They've clearly optimized the process for producing a lot of good-enough subtitles.

Adding $1k to each of those would be a lot of money. It's a little surprising that there's nobody pushing harder to get it done right on their prestige content, but the subtitling department is probably quite swamped with work as it is.