Many robots have no data

[leibei]

Neither does Google robot

[Thomas--F]

How do you use the Matomo-Tracker?
If you use the JavaScript- or the Image-Tracker, most bots will not appear, becaus the don't execute JS or load images.
You can get the bots only by using the PHP-API or if you import the server-visitor-logs.

Google uses many crawler to index different kinds of web-informations:
https://developers.google.com/search/docs/advanced/crawling/overview-google-crawlers
Most of them are identified by "Googlebot" or "Mediapartners-Google".
But if Matomo doesn't catch the bot-visits, the BotTracker-plugin cannot count them.