To sum it up I will enable lz4 compression to benefit from both reduced time and saving space. Also I'm planning to read wiki on how to safely disable fallback. I'm using LVM on LUKS method and I suppose fallback image cannot boot my Arch, so it doesn't help in case of an accident.
Removing fallback from /etc/mkinitpcio.d/linux.preset & /etc/lmkinitpcio.d/linux-hardened.preset PRESET which makes it like this and enabling lz4 compression reduced my time from 100 seconds to 20 seconds.
real 0m19.104s user 0m12.970s sys 0m7.856s