If you don't own the .com, you don't own the name, IMO. There are a ton of good .com brand names put there that are available, you just have to look. A unique name also makes your brand more recognizable, compared to ultra minimalist names like "Max" or "App" or something.
Not at all. If you decide on foobar.io, and someone else snaps up foobar.com, they effectively own the name foobar going forward. You're now in a tough situation of rebranding or trying to fight them to get the com.
Intellectual property laws, honestly. Peacefully coexisting isn't an option when you need to proactively defend trademarks to keep them. In such a dispute, holding the .com (with bonus points for defensive registrations across other TLDs) will grant you some favor.
