After careful consideration, the new UI on the Performance Lab settings screen to install and activate the standalone plugins was not the right call from a UX perspective. It is confusing to find the UI to install and activate plugins replicated in that area, and it fails to convey the point of why it's there.

We should iterate on the UI, to focus it on features rather than plugins.

The standalone plugins are, in a way, just a technicality. Their goal is to deliver performance features to WordPress sites in advance of a potential future WordPress core merge. Therefore, we should have cards of features, rather than cards of plugins. Under the hood, clicking the "Enable feature" button would still install and activate the underlying plugin. But that shouldn't be the focus of the UI, and it doesn't make sense to have it broken down into two distinct tasks either (install and activate can happen at once).

We can take inspiration from how Jetpack solves this problem. Consider the below screenshot:

Most of the cards refer to other plugins, and they are conveniently installed and activated under the hood. In our case, we wouldn't need a "Learn more" since all that Jetpack exposes there is information on the different plans and pricing, which doesn't apply here. We can surface sufficient information right in the card.

Let's focus this issue on implementing an MVP solution that revises the plugin cards to become feature cards, with plugin installation and activation happening in the background. We can reuse the existing design where possible (i.e. no need for different branding or anything).

Note: The modules part of the Performance Lab screen UI is being removed as part of #1029. So this can be ignored here as it will be gone soon anyway.