Does "Visited " shown on Google's My Activity mean that the app has been installed?
No, Google's My Activity showing &quot;Visited &lt;name of app&gt;&quot; on Google Play Store doesn't mean that the app has been installed. It literally just means that the app detail has been seen on the Google Play Store app, regardless if it's installed or not. In fact, My Activity doesn't even add any entry for app installation, so there's no way to know if an app is installed from there.
Alternative ways to know are:

Searching for &quot;Used &lt;name of app&gt;&quot; in My Activity instead
Browsing Google Play Store's My Apps. It lists apps that have been installed at one time unless the entry has been manually removed by the user from the Play Store app