Not even that, they optimize for acquiring and keeping subscribers. They gain nothing from you watching movies, it is just costing them bandwidth, at least on their ad-free plan, which was the only option until recently. It is completely different from YouTube and TikTok, or even oldschool TV, which get most of their revenue from ads.
They need a few good ones to attract new subscribers, and they do. Stranger Things and Squid Games are really good. For the rest, they just need enough content for people not to cancel their subscriptions.
If you want to encourage quality production, just subscribe for the month they are doing something good, ad-free of course, then unsubscribe. Many people are doing that, and maybe that's what it takes to get them to change their strategy. Maybe not for the better though.
Most people are probably lazier and less organized than you give them credit for. If subscribe/unsubscribe cycles were really that prevalent I think you'd see a lot more incentives to sign up for, say, annual subscriptions.
A lot of people basically use TV as background and, especially if they don't have live TV, that means a lot of streaming content.
People don't need more than one streaming platform for "background noise", and switching to the one with the most popular shows of the month makes a lot of economic sense. At the end of the year, it can easily save you hundreds of dollars, and the bigger the amount, the more people are going to do the maths.
Maybe an annual Netflix subscription is planned.