Samsung has chosen to go with more Microsoft integration (such as the One Drive tie up) primarily for Business reasons and there has been some demand from consumers for greater functionality between mobile and computing Devices. The strengths of both companies complement each other. Of course One Drive will not suit everyone but there are a variety of options for Cloud Storage. Like it or not this is the route Samsung has gone down. Some information in these articles . https://www.theverge.com/2020/8/6/21357163/microsoft-samsung-your-phone-ecosystem-office-365-integra... https://www.cloudduplicatefinder.com/blog/samsung-cloud-to-onedrive-migration-explained/
"A massive free cloud storage " would not be without offsetting costs.
The result would be more expensive handsets and in the pandemic the trend has tended to be in the other direction. Realise there is a demand for increased cloud storage but not everyone requires or needs huge storage.