If you want to build a library of high-quality, mature media, here are the safest and most robust platforms supporting "Olgun indir" style access:

Virtual Reality adult content requires massive files (8K+ per eye). As VR headsets become standalone, the ability to download high-quality VR scenes directly to the headset’s internal storage will become the standard mode of consumption, not streaming.

For independent mature films that are too risqué or artistic for mainstream platforms, Vimeo On Demand is a goldmine. Many directors offer direct downloads of their work in MP4 format, supporting the "indir" ethos directly.