It is said that only loaded files and their filepaths are stored in the active_plugins option in the database. The deactivated plugins only occupy a small file space in File Transfer Protocol aka ftp folder.
However, the deactivated plugin stored a lot of autoload data in the wp_options table.
If you don’t know what plug-in is slowing your site down, disable one at a time and test your page load speed until you find the plugin that is having the most negative impact on the loading time.
You can find out which plugin is taking up too much loading time with the help from Plugin Performance Profiler or P3 .