Bladers:
Its quite necessary coz you will need hot/warm water quite frequently. Such as for drinking, for making milk. However, which kind of hot water flask, it would depend on your household's personal preference.
For me, I have an electric kettle that boils water very fast + a thermal hot water flask that can keep the hot water hot for quite long + normal water flask for room temperature water. If need large amt of water, esp during confinement, I will oso have a big kettle on standby (borrow spare de from my mum).