[dakom]

It's not that it's incompatible, it's that when the ECS is the primary tool for organization, a DOM tree (or scenegraph) is merely one way of iterating over the entities - not the way.

This provides tons of benefits, so for example you can also decide to iterate over the entites by shader program and gain significant speedups for graphics processing, or maintain components that roughly sort them by their position in world space for physics and culling or lighting, etc.

For a crude analogy, imagine if Document.querySelectorAll() were a zero-cost abstraction, i.e. it ran as fast as iterating over linear memory. In practice this isn't how it turns out with an ECS, but it's much closer and you can get this kind of performance for the "hot path" kind of queries.

To add to the sibling comment, there's another wonderful Rust ECS called shipyard[0] and I helped write a scenegraph for it (which I really need to update, one of these days)[1]

[0] https://github.com/leudz/shipyard

[1] https://github.com/dakom/shipyard-scenegraph