I have see a trend where more and more people are securing their phones. I bounce back and forth between using a passcode and not.
My entires team (20 people) uses passcodes.
Do you or do you not?
What do you mean by "team"? Do you mean a team of people at work? If so, then this implies that you keep work data on your phone. If so - use a code.
If you have *ANYTHING* on your phone that, if it got in to the wrong hands, would be financially ruinous for you or any organization you are affiliated with (customer lists, emails about not-public internal projects, financial data, and
especially "sensitive" customer data like credit card numbers, social security numbers, or medical data,) don't just use a four-digit passcode, and don't use TouchID. Use a complex (arbitrary length, alpha-numeric) passphrase.
Depending on your company, you may be *REQUIRED* to use it if you use your phone for business purposes, and could be subject to termination if they find out you're leaving your phone unprotected.
If by "team", you mean a group of friends, then do whatever you want. (With the same caveats above.) One thing to remember, though - if you have no security, or easily-bypassed security, then anything
you can do with your device (post to Facebook, send emails, check your bank balance,) someone who steals your phone can do with your device.
If someone has access to your email, they also then gain access to the password-reset functions of most websites (such as your bank.)
(For the record, I use a separate email address as my 'password recovery' address than I use for anything else. It is using a different webmail provider, with a different password, than anything else. Even if someone compromises my phone, my home computer, my work computer, *AND* both my main personal and work email addresses, they can't do password resets.)