Can i use ”by” instead of ”through”?

Question

I saw this sentence

His proposals are expected to focus on improving quality through financial incentives

what is the difference if I write

His proposals are expected to focus on improving quality by financial incentives
?

Answer 1

If you use “through”， it feels like financial incentives is one of the way to achieve the purpose.
If you use "by", it feels like fincnical incentives is the only way to achieve the purpose.