I am missing my favourite plugins and the web interface is slow.
Volumio is not working for me anymore without the plugins.
I want to go back to volumio 2.x.
Where can I find the images?
Read the top blue banner of the forum, click and refer to the second post.
Note that support for Volumio 2 will discontinue soon.
Webinterface is “as slow” as Volumio 2 
What plugins are you missing? I’m only using GPIO Buttons on mine which are missing but not too difficult to add back in.
Plugins are supported by the community and I think some of the people who are maintaining them are preoccupied with other priorities. This page has the Plugin Status: Volumio 3 Plugin migration status
I think there is a link somewhere on the site to go back to the last Version #2 but you’ll have to keep an eye out for what’s going on and then upgrade because Version 3 is inevitable.