Similar experience so my advices are mix of Tech & Non-tech
1. Stop cribbing
2. Start using version control/git, Build Test/UAT environment
3. Upskill your team - As you mentioned your current team MUST have also inherited the code from someone else
4. Try tools like dead/junk code finder, lint etc
5. Try other refactoring tools and techniques
6. Most imp: Try to gain trust and Read 1.
A) Is current system stable [Understand it is messy!]?
If it is stable there are ways and means to build/design/architech parallel future roadmap without adding more mess.
1. Stop cribbing 2. Start using version control/git, Build Test/UAT environment 3. Upskill your team - As you mentioned your current team MUST have also inherited the code from someone else 4. Try tools like dead/junk code finder, lint etc 5. Try other refactoring tools and techniques 6. Most imp: Try to gain trust and Read 1.
A) Is current system stable [Understand it is messy!]? If it is stable there are ways and means to build/design/architech parallel future roadmap without adding more mess.