[Bug]: HEVC/AV1 encode is ~2-3x larger then AV1 source

### Which component impacted?

Encode

### Is it regression? Good in old configuration?

None

### What happened?

I am using some YouTube clips to test 8k -> 4k encodes and the overall best encoding settings to use.

When using landscape videos with slow moving content the output format (YouTube 8k60 AV1 10bit or 8bit -> HEVC_QSV 10bit) the end results are usually a smaller encode than YouTube. By a significant amount.

However when you throw a lot of fast moving content into the video (such as raindrops with fast movements) the output can be 2.5x as large as YouTube av1 video.

Example:
8k60 AV1 8bit (1.7GB size) -> 4k60 HEVC_QSV 10bit (4.37GB size)

Encode options on DG2/arc with linux:

"-pix_fmt yuv420p10le", "-global_quality 20", "-extbrc 1", "-b_strategy 1", "-look_ahead 1", "-preset 1", "-tile_cols 1", "-tile_rows 1", "-adaptive_i 1", "-adaptive_b 1", "-tier 256", "-mbbrc 1"

### What's the usage scenario when you are seeing the problem?

Transcode for media delivery

### What impacted?

_No response_

### Debug Information

_No response_

### Do you want to contribute a patch to fix the issue?

None