Comment by MaulingMonkey

    struct Entity {
        components: Vec<Box<dyn Component>>,
    }

At this point you're effectively just hand-rolling your own ECS - and perhaps being in denial about it by touting the fact that the ECS is half implemented at best - rather than eschewing an ECS outright, IMO. If you want to skip the ECS, embrace the natural typing of the language - then you don't need to build something to query and filter components, and can instead just use the language's built-in constructs:

    struct Entity {
        pub position: Option<XY>,
        pub sprite:   Option<SpriteId>,
        pub scripts:  Vec<ScriptRef>,
        //...
    }
    
    fn render_world(entities: &[Entity]) {
        for entity in entities {
            if let Entity { position: Some(xy), sprite: Some(sprite), .. } = entity {
                // ...
            }
        }
    }

Entity may eventually become a merge hazard on larger teams, and Entity enumeration without archetype filtering may eventually become a performance hazard if done too frequently and naively, but this kind of approach can work fine for many smaller projects.