I would even take your learnings from your experience a step further and say that one should be proactive in talking to teammates and exploring ideas on how to improve the codebase if you think there is room for improvement. For instance, it may well be that inheritance is the wrong pattern for that given codebase, but there are indications that the current architecture isn't scalable.
With more investment, more research could have been put into looking at better suited architectures such as the Entity Component System architecture, where Entities such as Rects and Ellipsis are composed of units of functionality (position, resizability, etc), which is a proven architecture for this sort of application. Then, implementation would be a matter of getting team buy-in / weighing the refactor pros and cons with your team.
With more investment, more research could have been put into looking at better suited architectures such as the Entity Component System architecture, where Entities such as Rects and Ellipsis are composed of units of functionality (position, resizability, etc), which is a proven architecture for this sort of application. Then, implementation would be a matter of getting team buy-in / weighing the refactor pros and cons with your team.
Tangential, but Entity Component Systems are a great way to structure systems with many types of entities that share subsets of functionalities. https://kyren.github.io/2018/09/14/rustconf-talk.html.