Piracy: ꜱᴀɪʟ ᴛʜᴇ ʜɪɢʜ ꜱᴇᴀꜱ

That is too broad of a question for a too narrow of an answer. You can answer with broad statements and generalized estimations, but I don't think they really answer the question.

Encoding video balances three things (extensible by two more):

• visual quality / equivalence
• size (stream/file size)
• encoding time
• decoding performance
• decoding feature set (compatibility)

The codec you use also has a high impact on compression ratio opportunities and capabilities. AV1, HEVC, AVC? 10-bit?

If we define that we do not care about encoding time, so we will use the very slow preset and use all codec features available, compression ratio and quality falloff still depends a lot on what you actually encode.

• Is it a cartoon with flat surfaces and mostly linear and partial linear or transformative movement? That can be compressed very well through differentials and transformation (movement).
• Is it a high-grain cartoon or movie? Fine, noisy details are hard to compress, they require more information.
• Does it have a lot of movement? A lot of vast movements and cuts? Less to keep and differentiate data with, so less efficient.

I suspect in higher resolutions the gaps between different visual data compression ratio differs more - because a difference is elevated through higher resolution/more data.

That being said, I don't have or use 4K stuff, so I can't even check for some rough numbers and visual content to size differences.