Agree that battlefield games look amazing and play smooth. And I'll allow 50 as close enough to 100. But the maps are not only smaller (largest I found was 1.5

Agree that battlefield games look amazing and play smooth. And I'll allow 50 as close enough to 100. But the maps are not only smaller (largest I found was 1.5x1.5km), but very different in nature: they are designed for traditional fps gameplay, and incorporate techniques to enable fast rendering (e.g. limited visibility so submaps can be streamed in as you move between regions; mountain ranges seem impassable, again forming a gameplay element and aiding rendering). The PUBG map is less "designed", and more like a real place. All areas are accessible, and although terrain undulations do eventually close-off areas, they are far larger areas, and they don't seem designed for rendering but for realism and a different kind of gameplay. Finally, a single figure to dramatize the map contrast: Battlefield 1 shipped with 9 maps. PUBG shipped with 1.