What does 'as favorable to' mean?

What is sure, is that Makan's quality of life can be considered better than that of most other peasants. We can rewrite your sentence in this way:

Compared to the quality of life of most other peasants in regions, that (the quality of life) of Makan can be considered as (being) favourable.

How much better it is, is determined by favourable. Cambridge defines it as:

giving you an advantage or more chance of success:

• favourable weather conditions

"Favourable" is not an Uncomparable adjective like irrevocable or dead can be. Therefore it has a positive connotation, but has degrees (more, less, (the) most (the) least). None of these were used, only the plain favourable was given in the sentence.

This determines me to say that Makan's quality of life was neither slightly better nor much better than that of most other peasants, but it was somewhat/significantly better. (Note that significantly is a higher degree than somewhat, it means "in a noticeably or measurably large amount" Merriam Webster, but it is less than much better).