I've been harping on their SideBar depreciation for a while now (FB9493574). The SideBar used to run up to the Favorites Bar, not the top of the app itself. It used to remember exactly where it was when last used on the Start page. Now the SideBar's reset every time you collapse it and reopen it again. And when you're relying on getting at months old links saved to your Reading List and it's now 5 Clicks (if you count clicking in the Search Field) instead of just opening a New Tab (One Click) and then clicking in the Search Field that's still, there from the last time you were on your Start page because it remembered.
The Start Page used to be GREAT! The SideBar remembering exactly where you were, even if you had scrolled thru a few months of links in your Reading List, AND the rest of the new additions to the Start Page and the device syncing along with the background image sync.. Just good stuff. But now with the SideBar changes, Safari's seemingly forced to be made to be in compliance with Apple's own Human Interface Guidelines, and now the SideBar no longer remembers where it was when I used it last. And I don't want to keep it open all the time, either. It used to JUST stay open on the Start Page and then would go away after clicking on a link or navigating away, allowing you to utilize the rest of your screen space. Safari is still better for me than the others, though. I do use Edge for work...