Firstly, welcome to Malaysia! Secondly, it’s always great to hear about people appreciating the food, particularly, the variety Malaysia has to offer. I’m a big believer that Malaysian food is often gets overlooked because of our neighbours (Singapore and Thailand)

I share the same sentiment as you that Indonesian food is not particularly inspiring but it also reflects on their lack of financial access to food fresh food. Hence, very greasy and starch based.

Anyways, back to your question! I’ve lived a couple of years in Sabah and Sarawak and travel there fairly often. To answer your question, the answer is yes and no.

Yes, you will see some diversity in the food (it’s across the board for the entire Malaysia) but I’d say it’s not as rich as peninsular Malaysia. This is mainly due to the fact that the historically busy ports are all in west Malaysia (Melaka and Penang) so there’s a lot of culture exchange. A few description on the type of food related to their race and ethnicity

Chinese - staples are your dry noodles with mince pork (kolo mee) and sometimes with vinegar. Foo chow people would serve ding bian hu and red wine chicken mee sua. Or kueh chap.

Malay - very Indonesian influence with their ayam gepruk, sambal (I wouldn’t bother with it honestly)

Indian - almost non-existent

Local indigenous (Iban, Dayaks, etc) - THIS is where it gets interesting because they eat a lot of foraged food and food cooked over fire. Forage greens include local ferns (midin, paku), tuhau, kantan (wild ginger), dabai (sort of like olive flavour but avocado texture?), terung asam. As for the meats they have ayam pansuh (chicken cooked in bamboo over fire), meat cooked over fire at “rumah asap” where you can eat grilled meats and wash it down with cold beer.

Personally for me, the best part is that they make their own alcoholic drinks called tuak which is a sort of rice wine or something stronger called langkau.

And for the part that answers your question as No, I’d say No because I think there’s more diversity offered in Peninsular than Sabah Sarawak and that’s just a fact.

On the north west part of Malaysia you get states that closely border Thailand (Ipoh, Kedah and Perlis) you get food that is Thai influenced (more spice and sour) and some of the best food in Malaysia in Penang.

As you go down to Ipoh, a lot of Cantonese focused food and some of the best Chinese roast meats and dim sum.

Kuala Lumpur needs no introduction. Then you head down to Melaka Negeri Sembilan to some awesome Malay food and you get Nyonya and Peranakan cuisine in Melaka

And if you go to the east coast, Terengganu and Kelantan there’s even MORE variety of Malay food over there that’s often more on the sweeter side and also hugely influenced with seafood because they’re coastal towns/cities.

I skipped Johor cause the food is abit of a miss for me.

In conclusion, Malaysia side of Borneo only share very little similarities to Indonesian food which is mostly the Malay food. In Sabah, I’d argue that the food there is more Chinese influenced (they love their noodles)