Correct about the servers because DT uses the MAC file system. Thus regular backups which everyone should have (ie Time Machine) you have a backup. Additionally, sync to your IOS devices is via iCloud. While not a backup your info is in the cloud. Re Web access you are correct unless you spring for the most expensive version of DT. Note that using the MAC files system then you have access to all your notes via the FILES app.
prepare yourself to move to Devonthink. Pricey but has more automation than Evernote legacy ever had plus lots of other great features. Beware, Mac and iOS only.