Plugin count is not a performance metric. One plugin might barely participate in a request.

Another might hook early, load assets everywhere, query the database globally, inflate autoload, and trigger background API calls.

Both count as “one plugin.”

The real question is not how many plugins you have. The real question is what work they add, when they add it, and where that work runs.

Learn to diagnose plugin cost properly:
https://withinwp.com/courses/make-wordpress-fast/