I realise that Google places ads in the native Gmail environment. However, when using a third party front end to embed the Google services, how does the company make money off that? When I use Thunderbird to access Gmail or the Google Calendar or when I map my Google Drive to the file explorer, how can Google profit from this kind of use?
Could be a loss leader to suppress competition and own the market, getting you into their other paid services. They probably also profit from your data either directly or through things like training AI.