The consequence people discover later.
WHAT HAPPENS
Content built with a third-party builder is stored in that builder's format.
Deactivate the builder and pages display as unreadable markup or empty.
WHY
The builder stores layout instructions the rest of WordPress does not understand.
WHAT THAT MEANS PRACTICALLY
Changing builder means rebuilding every page Stopping paying means the site breaks Changing theme may break layouts
HOW BAD IS IT
Varies. Some builders export more cleanly than others.
None make it painless.
HOW TO DECIDE
Ask what happens if you stop using it.
If the answer is that your pages stop working, price that in.
HOW TO REDUCE EXPOSURE
Use the built-in editor where it suffices Use the builder only for pages that genuinely need it Keep content in standard posts and pages where possible
FOR A LONG-TERM SITE
Lock-in matters more the longer the site lives.