apparently not all #usb 2/3 to #vga/#dvi/#hdma adapters are the same
DisplayLink (for example)
DisplayLink USB graphics technology is a unique approach to USB graphics, allowing smooth video playback and providing a low latency connection that feels very much like a traditional monitor while providing the “plug and display” simplicity of USB. DisplayLink USB graphics technology allows for high resolution, full 32-bit color graphics, at resolutions up to 2560×1600 (depending on chip used).
not to be confused with
DisplayLink even do a USB 3 to HDMI 4K adapters