I agree, but also Android is a Google's OS. It's just the HW manufacturers put a skin and their own apps/services on top of it. There are also a few Chinese OS's based on open source linux mod, as is the Finnish Sailfish. Then there are number of simple 'dumbphone' OSs with the cheap feature phones. There is the open source Linux OS Tizen. However coding drivers to maximise the HW opportunities is very slow on these as they don't come pre bundled with phone.
iOS works well for its users, because of the tight SW - HW integration. This also makes is more secure, but also limits the options. Google Pixel phones tend to work really well as they order the phone HW based on their new Android version, whereas Samsung & al need to optimise their HW based on the latest/upcoming Android version.
But if we at least have different equally competing ecosystems (as we do now), then we have decent competition.