I use Simplenote as well. I find it to be a simple, no-nonsense product with everything I need.

The editor understands Markdown, and you can make a note into a webpage with a single click, for free. Notion, Obsidian charge money for this.

I use Simplenote when I attend talks to take notes. Or make small listicles.

Their support is fantastic, too. Despite it being a free product, support responded to me every time I reached out to them (thrice in last 4/5 years), and promptly solved my problem.