This very same Idea was closed last year, unfortunately. However, I would encourage you to vote on and add your comments to these related Ideas/discussions:

Ability to set Default Privacy settings by activity type, recording device, tags or other criteria

Privacy settings for new uploads

Set activity privacy and map visibility via API

Hello ​@windharness 

Thanks for your post. You can edit the activity privacy control on each activity using our Quick Edit screen

Quick Edit is a fast and easy way to set the privacy control on each activity. 

Additionally, it’s always an option to set your activities to automatically import so they are visible only to you. You can then edit the ones you want others to view and change the activity privacy control.

Changing Your Default Preference
Your default preference is the setting used on any new activities uploaded to your account. Updating this setting does not retroactively change the privacy controls on past activities.

• On the web, go to your Settings page by hovering over your profile picture in the top right and selecting “Settings,” then click on “Privacy Controls” on the left side of the page.
• On the mobile app, open your Settings from the icon in the upper right corner of the You tab. From Settings, select “Privacy Controls.”
• Select “Everyone,” “Followers,” or “Only You” under “Activities.”