If your threat level requires apps to be running in a profile without play services installed at all (even if you're not logged into an account, where play services is sandboxed where the only permissions you grant are network and notifications, and possibly a trusted VPN running at all times), you may want to utilize Private Space as a more convenient alternative to a second user profile.
You need to assess what you're trying to protect. There is a tradeoff for usability and privacy/security - you don't want to unnecessarily cause privacy fatigue. Just using sandboxed play services and revoking permissions is already much better than using stock.
Depending on which apps you use, you can designate the Owner as your play services profile and your Private Space as your non-play services foss apps or vice versa. You can set Private Space to just close on restart so you don't need to keep opening it as often.
and it'd be frustrating using Reddit on another profile if I wanted to share a Reddit link with someone via Beeper, for example.
Social media apps in particular are known to be terrible for privacy. You can use a privacy focused front end (if they still exist) or just use reddit through the browser such as through a Progressive Web App (PWA). In a browser, go to reddit.com and hit the browser menu button, then "Add to Homescreen" or "Install App." It will look look similar to an app, but it's actually running through your browser without needing to install anything. You just won't get notifications from reddit while the browser is closed, but reddit I think gives you the option to have notifications emailed to you if those are necessary.