Not really a full manopoly. Can't really blame TNB just that nobody wants to set up their own company and pull new cables and high tension towers. Nobody. Recently I read gov has forced tnb to allow 3rd party access to power plants that want to piggy back tnb network, but so far nobody is doing that for residential customers.

Same case with internet, only new one is time fibre. Others like maxis and celcom all piggy back on TM's unifi infra and cables.

So far I only know Genting have their own power plant, network, substation, towers and is supplying to their residents, condo and their own theme park.

In Singapore they have many companies because the island is small and it doesn't take much money to build cables spanning the entire island to supply to all customers especially when they are all condos.

Gov should give subsidy/incentive to produce another player in electric, just like how they set up DNB for 5G. Then only got competition and more choices for us.

Edit: I was curious and went Google, apparently there's over 300 active license holder to sell electric in Malaysia
https://www.st.gov.my/web/general/details/993