The path to upgrade enlightenment
Umbraco 8 introduced the need for syntax updates to the code of older sites and a new look for the CMS and a lot of new features to make content editing quicker and easier.
Umbraco 9 saw the switch to .NET Core from .NETFramework, a fundamental change in codebase that requires a rewrite of more than just a few lines of code. Moving a site from 7 to 9 is the most difficult part of the upgrade process but once your site is on Umbraco 9, the steps to 10 and 11 are relatively simple and the path to future upgrades is smoothed by Umbraco's decision to have their improvements align with .NET's upgrade path.
We know it's a lot of numbers and talk about paths and code, but upgrading your website to at least Umbraco 9 will ensure it remains secure whilst being easier to maintain in the future.