Each redirect costs a round trip.
WHAT A CHAIN LOOKS LIKE
http://yourdomain.com to http://www.yourdomain.com to https://www.yourdomain.com to https://yourdomain.com
Four requests before the page begins loading. On a mobile connection this is noticeable.
WHY IT HAPPENS
Separate rules added at different times: one for www, one for https, one from an old migration, one in a plugin.
FIXING IT
Combine into a single rule that goes from any starting form directly to the canonical https URL in one hop.
Remove obsolete rules from previous migrations, which frequently survive for years.
CHECKING
Use a redirect checking tool. Enter all four starting forms and confirm each reaches the destination in one hop.
ALSO CHECK INTERNAL LINKS
A link in your own content pointing at http://yourdomain.com/page sends every visitor through a redirect. Update internal links to the canonical form rather than relying on the redirect.
THE PAYOFF
Removing two redirect hops from every page load is a real speed improvement, and costs nothing.