If you look at the complaints about Netflix, most of them relate to content, not tech. This suggests that they've under-invested in content, and over-invested in tech.
Disagree, total content spend the last 4 years has been ~18bn/year compared to ~500m/yr on all employee R&D. That's shows there's a content quality problem not a content underinvestment.
According to their latest annual statement (2022), they spent 2.7 billion USD on "Technology & Development". Where are you getting the 500 million figure?