The de minimis treatment has been abused beyond original intent. Specifically by China, but you can't fix that without fixing the general case.
Fast fashion and other low-value drop air shipping across oceans is ecologically insane: as a planet we literally can't afford to keep doing this. And the US, by virtue of population + relative consumer wealth, is the biggest customer for this.
Furthermore, the inability to reliably screen low-value packages is a problem. To wit, I should not be able to order illegal drugs on the internet and have them delivered by the federal postal system to my door without inspection.
Unfortunately, the way to actually address this requires thoughtful regulation (Congress+customs), modernization and funding of enforcement at scale (Congress+customs), and doesn't produce a quick win... so isn't going to be done.
More likely, it's used as a bargaining chip in trade negotiations, then the problem is declared "won", then it's back to business as usual.