Malaysia Google data centre will be build here in PD instead of Elmina Selangor.

Why PD,
A.nearer to international submarine cable s landing point.
B.Near to water source, can use sea water after desalination for cooling purposes.
C.Near to Tuanku Jaafar Power Station (TNB) at PD.

Maybe as a warehouse.

Google is building a large data center in Port Dickson, Malaysia, as part of a wider US$2 billion investment in the country's digital infrastructure. This data center, to be developed by Gamuda DC Infrastructure, will be operational by the fourth quarter of 2028. Additionally, Google has a data center under construction in Elmina Business Park, Sungai Buloh, which is set to be completed in early 2026.
Elmina Business Park Data Center:
Google's first data center in Malaysia is being built in Elmina Business Park, Elmina, Selangor, with construction completed in early 2026. This data center is part of a US$2 billion investment by Google in the country.

Port Dickson Data Center:
Google is also constructing a hyperscale data center in Port Dickson, about 90 kilometers south of Kuala Lumpur, in collaboration with Gamuda DC Infrastructure. The treatment plant for this facility is expected to be completed by the second quarter of 2027, while the storage facility is expected to be operational by the fourth quarter of 2028.

So I believe the one at Elmina will be act as warehouse, DR cold site. The one at PD is hyperscale DC. Hyperscale DC is more bigger than normal DC. It can host high numbers of server, storage, networking and can scale up according to demand.

You need to think a little bit more.

What is actually going on in all these "data centers"? Why do they need so much resources/land/energy for a "data center"?

Until now it isn't clear what are they doing in these data centers...