Why your website is slow, and what actually fixes it
Speed matters more than most people are told. Visitors leave slow pages, and Google factors loading speed into where you rank. The frustrating part is that the usual advice, buy faster hosting, is normally the least effective thing you can do.
It is almost always the images
This is the big one, and it is boring, which is probably why it gets skipped.
A photo straight off a modern phone is often four or five megabytes. Uploaded as-is and displayed in a box a few hundred pixels wide, the visitor still downloads the whole thing. Ten of those on a page and you have a page that takes fifteen seconds to load on a phone signal, no matter what you are paying for hosting.
Resizing images to the size they are actually displayed at, and saving them in a modern format, routinely cuts page weight by eighty or ninety percent. It is the highest-value hour anybody can spend on a slow site.
Too many plugins doing too little
Every plugin adds code to every page, often whether or not that page uses it. A site that has accumulated twenty-five plugins over four years, several of them doing overlapping jobs and two of them abandoned by their developers, is carrying a lot of dead weight.
The fix is unglamorous: go through them, work out what each one is actually for, and remove anything you cannot justify. Do it on a copy first, and have a backup.
Page builders that were never tidied up
Builders are not inherently slow, but they make it very easy to end up with nested containers ten levels deep because somebody kept adding rather than restructuring. The rendered page ends up carrying far more markup than the content needs.
What to do about it
Run your homepage through Google PageSpeed Insights. It is free and it will tell you specifically what is slowing your page down rather than leaving you guessing. Look at the mobile score, not the desktop one, because that is where most of your visitors are.
If the report is mostly complaining about image sizes, that is good news. It is the cheapest problem on this list to fix.
If your site is old enough that the answer is “all three of these”, it may be time for a rebuild rather than a repair.