I think one of the things that GA is doing is actively removing bots visits because they skew country/browser/etc. data. Maybe Matomo is not doing that (so well

I think one of the things that GA is doing is actively removing bots visits because they skew country/browser/etc. data. Maybe Matomo is not doing that (so well)? Another thing is that people blocking GA trackers will also not show up in GA, but will (probably) show up Matomo.