Improve video quality from PC to TV?

I want to connect my PC to a Samsung smart TV (q90r) and play videos from Netflix or other services.

I connected my PC to my TV and graphics card with an HDMI cable. Picture is 4k with 30p, I do not need more because I play only 24-25p videos.

If I now play a video in 1080p or 4k, then it is the picture quality significantly worse than if I stream it from the TV itself or my phone on the TV. Of course I have the TV, for the PC, the same movie settings as the other devices. The picture is always a bit washed out. Have my computer then connected to my old TV, because the picture was synonymous worse.

Is only for videos. Pictures themselves look quite normal.

My PC:

I7 9700K
GTX 980ti
16gb Ram
Windows 10

Does somebody has any idea?

I could imagine that this may be due to the bitrate, which is present in the video streaming and perhaps also because the image is still transferred to your TV and thus more pixels are missing or blurred.