What might be alluring employees to return to the office full-time?

Admittedly, being with other people is likely the only real draw at this point. Everything else seems rather secondary.

The office provides comfort:
Comfort that you're being seen
Comfort in connecting with other adults
Comfort and validation for your work or thoughts in real time
Comfort and a change of pace from the same old spot at home

Alternatives:
Alternatives to PB&J sandwiches 
Alternatives to arguing with your spouse/partner/kids

I polled some people who are coming back to the workforce and around 71% of the people who wanted to come back to the office either had babies or teenagers at home. So you can imagine why they want to return to the office. They just need to get out of their homes and be in an office where they can relax. They're looking at the office as a place where they can feel less stressed out.