important for/ to sb

[joham]

These rules are most important for you, gentlemen, although they are important for the ladies as well.

The above sentence comes from CAE. But I read in OXFORD DICTIONARY the sentence: It is important to me that you should be there.

When should we use 'to' or 'for' after 'important'? Could I say it was because we could say
'These rules are most important for you (to obey/ follow), gentlemen, although they are important for the ladies (to obey/ follow) as well' that the 'for' should be used?

Could I ask native English teachers to help me please? Thank you in advance.

[David L.]

Something is important to a person because they value it.

Something is important for some purpose.

eg

That may not seem much to you, but it's important to me.

These rules are important for the safety of all on board the aircraft.