I am working on the BotPenguin chatbot plugin for the past 1 year and got 3k+ downloads, and here are my observations.
- Regularly Update your plugin with recent Tested up to Recent WordPress Updates
- Collect Reviews for your plugin
- Resolve queries/complaints on your plugin
- Make sure PHP Version is lower as possible
- Use Proper Tags For your Plugins
Here is my chatbot plugin https://wordpress.org/plugins/botpenguinbot/