I personally am fine sticking with Gmail as I really enjoy the interface/features. One of the things I really like is the scripting I can do with Google Sheets,

I personally am fine sticking with Gmail as I really enjoy the interface/features. One of the things I really like is the scripting I can do with Google Sheets, Gmail, and my Google Calendar. I have some pretty nice automations setup that do things like automatically adding details to my calendar based on emails. Parsing emails to put data into a spreadsheet, automatically adding details to calendar entries for certain things, etc... What I do to avoid too big of a headache with a lockout is using my own domain name. I essentially just forward my emails to my Gmail account. And then I set it up so I can reply with my own domains address in emails. So if I want to switch to a different provider it's just a matter of switching where I forward to or switching mx records. I also use Google takeout to take frequent full backups of all my data.