Taiwan also doing the same, instead of building proper frigate they opt for Tuo Chiang missile corvette....
My best guess its faster abd cheaper to be built in quantity, also assuming our enemy already invaded in IDN sea teritorial.
Because they know they will be overwhelmed + the invasion of Taiwan is not a matter of IF but WHEN. We are not in any way under possible imminent invasion, the navy should be geared the way that other navy which in particular have problems with PRC but not under imminent assault, like Japan, South Korea. In short Taiwan navy has only one mission, while ours has many. The Taiwan navy is akin to the Volkstrum of Berlin in the end of WW2, their gear is wholeheartedly designed to defend and to be cheap, we do not.
The navy has a lot more to do other than preparing for an all out hypothetical invasion. It ships could be used as additional air defense battery, additional eyes and ears for the country with their sensors, casually interdicting enemy shipments etc. Taiwan doesn't have/ no longer could afford this luxury for their navy.
Look at Japan, they're building 2x 20k tons ASEV + 2 additional 10K tons AEGIS destroyer in addition to an even more sophisticated improvement of the Mogami. For shore defense they opted for more truck launched missile instead of building more Hayabusa's, beacuse their navy is the backbone of their defense not some last resort military option.