What resolution should I use for images on the site?

Question

Layout

The site has a fixed-width container. Depending on the width of the screen, its width changes.
1170px is the default width.
940px - if screen width <= 1200px (media query max-width: 1200px).
720px - if screen width <= 992px.
Next - 100%, but left and right padding'i 15px each.

Inside the container is text and pictures.
What resolution to use for pictures?

It seems to me that it doesn't make sense to use images with a resolution greater than 1170 in width, since they will still shrink to this width to fit into the container.
But there is another opinion - on high-resolution phones, pictures will not look very good.

But I don't have a high resolution phone. So I can't check.
What opinion is true? If it's not difficult, can you provide links where it is signed?

Answer 1

The resolution on all smartphones is almost the same, the average is 360px