I was wondering if it was like all the kernel/systemd/etc messages or just a line or two line “Boot Cachyos..”
But it sounds like it may be the former.
So a few things .. if you want plymouth then you can follow the reverse of the following guide (make sure the packages are installed, that the hooks are included, etc);
On the other hand if you dont want the boot splash animation and you want things as silent as possible then you could follow: