celcomdigi have hidden wireless mobile plan RM14 2000GB 9 days
To get stable 100mbps need high end 4G modem like huawei b5xx or 6xx series.  But the modem price can get 5G modem

Cheap 4G modem viral on tiktok dont give stable 100mbps speed

RM1 / Day is a surprise deal and may not be always available

I'm using RM1 1TB / 9 days nearly one year
I'm not an heavy user, work from home but kids watch a lot of Netflix and YouTube without any issues

One minor issue my 3UK 5G router may not be stable all the time, but I use ChatGPT to help me write a script to reboot it daily and so far no issue.

Noted that Digi provide credit rebate sometimes, make some calculation and use it wisely.