There are also "third ways", so to speak, ways to have people feel comfortable without resorting only to least-common-denominator "harmless" topics.
I have been a regular at several places (sometimes coffee shops) across the country where I can sense very real substantive conversations. Sometimes people just need a little nudge to get out of their comfort zone.
Such interactions can help bring people even closer. It takes intention and some experimentation.
In most social situations "heavy" discussion or "debating" is entirely unwarranted and brings the overall mood down.
There are plenty of discussion groups and meetups if you want to hotly debate politics or suchlike!