It depends what you want, and it probably dependent on how this Fall goes. Likely no indoor attractions are going to be operational, and as noted other than sporadic sidewalk seating fine dining is a no-go. Some of the 'big' touristy stuff may be open - i.e. Pier 39 recently reopened. Outdoor tastings are popping up in wine country as well
It could be a good time to do outdoorsy things, but the variable is you don't know if the parks will be open. For instance, some were closed to car traffic, but then access was pretty glorious by foot/bike. That said, San Mateo county was so fed up with people during the initial days of the lockdown they were stopping cars and asking for proof of residency in the area, and even cyclists were ticketed riding down from SF. In general, or at least at first, CA didn't suffer fools - we locked down.
You certainly could still walk around the city, and some sites will always be accessible, but boy these are strange time - a lot of what makes SF the tourist draw is not open at the moment. As noted, great for us 'locals', though.