Honestly leaving salesforce is a piece of cake if it weren't for the ecosystem of other tools and integrations. A few years back I did a simple export of all our salesforce data and made a demo of a salesforce clone and if that wasn't good enough it was easy to import into sugar crm. 1 out of 40 salesman complained it wasn't exactly the same so they stayed and went full force with plugins and now it's a web of plugins that's harder to escape. As soon as a salesman sees a ad for "this plugin will make your life easier and your job " it's done, they setup a demo with our CEO and beg for it like it's a Christmas pony.