95kB doesn't seem unacceptably high. Most extensions aren't problematic on their own, but it can add up with many extensions.
A few extensions load their dependencies asynchronously and/or using webpack chunks so they might indeed appear lower in the report while still being huge in practice. But since the dependencies as loaded asynchronously they don't slow down Flarum initial loading, and might not be loaded at all if the feature is not used by the user.
The assets report is still very important to see what has the biggest impact on initial page load.
The lab is not taking into account any external library loaded synchronously via a separate <script> tag however (inserted in the <head> for example). That would also slow down Flarum initial load.
