Dealing with legacy systems: when to rewrite vs incrementally improve

we're dealing with a really old PHP monolith, probably 10 years old now, minimal tests, and a lot of outdated dependencies. it's causing constant pain for our dev teams. management is keen on a full rewrite into Go, seeing it as a fresh start. however, i'm acutely aware of the 'second system effect' and the numerous failed rewrite projects i've read about. my team is pushing for incremental improvements and strangler fig pattern, but it's hard to get that message across when a full rewrite seems so appealing on paper. does anyone have a good framework or set of criteria for deciding when a full rewrite is truly justified versus when incremental improvement is the safer, more pragmatic path? how do you build a compelling case for one over the other?