I use both Bear and Obsidian. I do some long-form writing in Bear but keep all of my structured notes and markdown in Obsidian. Obsidian has much better tooling and many more features, but Bear has a very pleasant experience for writing. It's very simple but if it's all you need it's very polished.

If I had to choose one I'd use Obsidian because Bear's features are a subset of what Obsidian does, but Bear is still nice.