A few years ago I was evaluating options to move away from a deprecated external latex library my company relied on in Confluence, and tested Notion. I was super impressed at the rendering speed of their latex implementation (KaTex of course). As other have mentioned, not everything is there, but it was sufficiently good for our purposes. The switch was a pain, I hoped that Notion had good tools to move over from Confluence, but we had to do a custom job relying on sketchy undocumented APIs