Although the following article mentions iOS (which I don't use), I learned some things about reopening tabs in MacOS Sierra. For me, it's useful stuff. How to reopen tabs in Safari for iOS 10 and macOS Sierra

Thanks for passing that along Jon. Once you brought it up I went looking and found three Safari features I was unaware of…

1. On MacOS 10.12.2 beta and iOS 10.2 beta and the recently closed icon (+) shown in the Apple Insider tip does not appear in Safari 10.0.2, Safari Technology Preview release 18 and is not available as a custom icon. However, on both the Safari and Safari Technology Preview menu bar you will find History âž­ Recently Closed with a laundry list of recently closed Tabs/Windows.
2. ⇧⌘T will reopen the last closed window.
3. When I was looking for the icon shown in the article I discovered another feature I had previously overlooked in Safari on MacOS and iOS. There is a Show/Exit tab overview icon (❐) that lists all the currently open Safari tabs/windows on every device associated with the same Apple ID. Clicking on any of those opens the specified tab/window on your current device.

Features get added, subtracted, and sometimes re-added in Apple's beta testing process. Personally I hope these features as implemented in the current betas will prevail.