Hello rainlofi0703, welcome to nixers.

Distributions cater to users, they are more shaped by them than the users shaped by the distribution. So maybe try to find users that have a need for minimal systems, it could be the embedded system engineers or others. We had a thread in that spirit here, take a look it can inspire you.
NetBSD thrives on all sorts of small hardware, so maybe give it a shot or check other distros that can be embedded into hardware.