meaning - What’s the difference between “for” and “to” in “for/to many people”?

Given these two versions of a sentence:

For many people, dogs are the best friends.

To many people, dogs are the best friends.

I have following questions:

1. What is the difference between using for and using to for this sentence?


2. Are both versions grammatical?


3. If not, which one should be used and why?