This is a "traditional" political stunt in Singapore.
It serves no practical purpose; it is purely a political show.
Singapore is an extremely wealthy nation. For its government, a VIP private jet is the equivalent of an everyday passenger car. Yet, these politicians choose to do the exact opposite by publicly flying on budget airlines. This is a classic political stunt.
Let’s be realistic! For politicians, safe and efficient modes of travel should always be the priority. The specific method of transport chosen should simply be appropriate given the nation’s overall circumstances. For a politician from a highly affluent country to deliberately opt for this approach clearly contradicts basic common sense. There is only one reason for such behavior: a political stunt.