Lightroom isn't a pixel editor like Photoshop or Affinity or Pixelmator.
In fact, it's a more robust version of Photos itself: that is, it's a parametric editor. The advantage of this is your original images are never touched, and all editing is non-destructive. To achieve this both apps are built on databases. However, like all databases, the only way the app can work with the data (in this case your photographs) is by importing it. And the only way it can share the data is by exporting.
With a pixel editor Photos ( or LR) can send the image to the editor, and after editing, a save will send the image back to Photos. This is not possible between LR and Photos.
In fact, there is no sensible way to use the two apps together - they both are photo managers and both are parametric processors. They both occupy the same place in the workflow. It's a bit like trying to maintain two completely separate address books or write your novel in two different word processors at the same time. It only leads to confusion and complexity.
So, there are only "work arounds". There is only the export/import/export/import dance.
As an alternative: any pixel editor you choose.