Yes.. I recall my Sarawak friend lamenting that fact. Sarawak is a resource rich state and has been one of the cash cows for Federation government.
Of course when sabah and sarawak merge with singapore to form malaysia, singapore was the rich state with USD400 mil in reserve.
Sabah and sarawak on the other hand were poor at that time. No huge gas field yet. it as producing oil but a a meagre rate. and timber was their resource which is controlled by the state.
The story was that LKY refuse to share singapore's wealth with sabah and sarawak.
Today, its a different story. Thanks to BN affirmative policy, the terminal in bintulu is probably the largest LNG exporting facility in the world. the ibans got their jobs working in oil and gas and shell was required to hire bumis at a certain quota and contractors must have bumi quotas which translate into bumis starting their own oil and gas companies and now some of them are going worldwide providing oil and gas services.
brunei, for so long dominated by contractors from singapore, has only started their affirmative policy due to reluctance by Shell brunei. you can use this as a gauge to see if oil and gas benefited local bruneians as much as it did sarawakians, who now can build their own offshore vessels and platforms.
If sabah and sarawak had merged with singapore, all the jobs will be controlled by the chinese and the shipbuilding of platforms will be done in singapore like what is happening in brunei.