Safari "Improvements"

I have always believed in the old adage "If it ain't broke, don't fix it"! I'm wondering what was broken in Safari that prompted Apple to "fix" bookmarks so that they collapse and reset whenever the app is reopened! Also, why can't I hit the back button and return to the place where I was on the previous? I don't have these problems while using Firefox or Chrome. These issues occur on my iPad and my IMac. I would like some clarification as to why these "Improvements" were necessary!!