Hi all,
why KaOS doesn't provide a linux lts packages? I have read about linux and linux-next in docs. thanks.

Make sure to read how Linux is handled:
https://kaosx.us/docs/kernels/

There has been an lts kernel in KaOS, but repo size will never exceed to what it is now, so packages not used are replaced by those that have users. Linux-lts was not used at all, most probably since linux itself is already updated very conservatively.