Aren’t we all? Windows’ media player uses hardware-accelerated decoding but Shotcut does not. Hardware-accelerated decoding only makes sense when you can keep the entire processing pipeline in the GPU memory including all scaling, filters, and track blending and do the processing using GPU. Shotcut is not there yet because editing is so much more sophisticated that simple playback. It has some GPU Effects mode, but that is hidden due to bugs.
Actually, FFmpeg and VLC does support hardware-accelerated decoding. Shotcut does not yet though for a few reasons. One is to figure out how to convert the image from hw decode to OpenGL text for the GPU effects in a cross-platform and cross-API manner (every combination of Intel, Nvidia, and AMD for Linux, macOS, and Windows). The other is to figure out how to limit this with respect to multiple video tracks because many systems have limited resources for hw decode. The last reason is due to lack of time and energy since GPU effects need to be more stable first, and that activity needs to follow stabilization without GPU effects and general bug fixes and basic expected features.