Obviously for monetary reason. Instead of allowing one time fee of rm30, they want customer to reload rm30 every month. And its stated in their tnc, something like we reserve the right to change plan bla3 without notice bla3. Celcom and maxis did the same. Unless wanna bring them in court to decide whether those tnc is valid or not, most ppl just took the easier no hassle route, ported out to other telco with long validity.

Its usual business tactics, to relief them from liability. Every telco got those cliche wording in their tnc. Whether those one sided tnc is valid and fair is another story, only court can decide. Thats why like i said earlier, instead of dealing with hassle of court, time and more money to hire lawyer etc most ppl just outright port out to another telco that still have validity extension. If one really does have the time, the money and the patience to bring them to court then i wholeheartedly support the action but i bet no one would.

By the looks of it they're trying to phase out the validity extension all together. Instead of sudden removal they chose to raise the fee exorbitantly, or keep the price same but make it into the uncertain, non-guarantee forever bos.

They've made a promo for the rm108 365 validity, discount 50% but as usual like the bos rm38, no guarantee this will be available later next year if u wanna continue.
https://amanz.my/2023377538/

If the bos rm38 doesn't come with basic internet, this should be okay-ish since i think it come with some sort if connectivity too. If the bos rm38 got basic internet then bos is cheaper.