Good programmers know that a lack of superficial code quality and consistency is the best indicator of deeper systemic problems in a project. If you ever need a quick estimate of the quality of a codebase, this is what you should look at first.
Rails Long Term Support
Rails LTS provides security patches for old versions of Ruby on Rails (2.3, 3.2, 4.2 and 5.2)
Prevents you from data breaches and liability risks