I think you're too quick to point fingers and too desperate to throw people under the bus to pass yourself as saviour.
There are plenty of everyday scenarios where software piles up technical debt in spite of the developers. All it takes is a single requirement to change for an entire tech stack to become a problem instead of problem-solver, and all it takes is a business goal to be met at record time to pile up quick-and-dirty solutions instead of well-architected implementations. These happen far more often than replacing whole teams, and new project leads solve nothing.
I've worked on a legacy project which started as a multi-platform desktop app that in the meantime became Windows-only. You can imagine the cruft that resulted from this requirements change alone. During the same period, business requirements changed to support new major features, and Microsoft started pushing for Windows 11. Of course we discussed a major rewrite, as the legacy tech stack didn't supported native Windows features well and the legacy application was riddled with multi-platform code that made no sense anymore. Switching to vanilla WPF alone would eliminate 90% of the project's pain points.
Tell me exactly how the team created this problem, and how you would be the key to fix it.