The helpfully named site AlternativeTo is good for such questions. It's populated by users and served me well over the years.

IFTTT and Zapier are the primary non-self-hosted alternatives, both have been around for ages and have lots of available integrations.

Node-RED and Huginn are the self-hosted alternatives. Huginn is older than both n8n and Node-RED, afaik, and seems to be primarily focused on online queries like updates to a webpage.

In the end I haven't used any of the self-hosted ones, since I'm more of a code guy, so can't say if one is better than another for anything.