Everybody wants to argue about which page builder is best. Wrong argument. They all build pages. That was solved years ago.
The real question is what happens after. When you leave, when I leave, when somebody has to open this in 2030.
The test
Turn the builder off. What do your pages look like.
The good answer is messy but readable content. Headings, paragraphs, images, in order. You could rebuild from that in an afternoon.
The bad answer is a wall of bracketed shortcodes. Not content. Instructions to a program that is no longer installed. That is not a migration, that is retyping your entire website.
Roughly how they sort out
Native WordPress blocks leave the cleanest exit, because the markup is standard HTML stored in your content. Least flexible, best long term position.
The class based builders that output relatively lean markup and let you work with a real design system are the sweet spot for professional work. You still have a dependency, but the output is sane and the structure is yours.
The shortcode generation is where it gets ugly. Powerful, popular, enormous ecosystems, and leaving means rebuilding. If you are on one and it works, that is fine, keep going. Just know the exit cost before you build fifty pages.
The performance side
Some builders wrap a single paragraph in five nested divs with generated class names. Multiply that across a long page and you have a document that is mostly scaffolding.
That is real weight, and it is the kind of weight caching does not fix, because the browser still has to parse all of it.
The part that matters more than the builder
Discipline. I have seen beautiful lean sites built on builders I do not love, and absolute disasters built on the ones I do.
Global styles instead of styling every element individually. A spacing scale instead of eyeballing every gap. Reusable pieces instead of copying a section eleven times and editing each copy.
A careless build on the best builder is worse than a careful build on a mediocre one. Every time.
So the tool matters. It just matters less than whoever is holding it.