Why would indices be affected by trendlines and support/resistance lines?

Beginner Questions
1

For instance - the FTSE 100 or the dollar index. Given that the people betting on the index moving up and down don’t move the market. Is that correct? The only thing that moves the index is the underlying group of markets.

So yes, why would they be affected by trend lines or support/resistance lines?

2

edit:
deleted
what a waist of time

3

Don’t think you understood the question . I know all what you said but why does it apply to indices when people who trade indices don’t affect the index market.

4

you didnt understand the answer