IMO after launcher is optimized to be truly idle while there is no interaction with it shaving memory usage becomes more important for snappiness and battery life. Extra RAM that launcher uses it the same RAM that other apps cannot use and therefore become more laggy. I expect on average shaving off 100 MB of launcher RAM usage will save more battery then reducing time for rendering its window by 0.1s
Or after a while without interaction bloated RAM get swapped out and launcher invocation need to fetch swapped out info.
For comparison here is how krunner looks on my current machine. After some time without interactions:
$ systemctl --user status plasma-krunner.service|head
● plasma-krunner.service - KRunner
Loaded: loaded (/usr/lib/systemd/user/plasma-krunner.service; static)
Active: active (running) since Sun 2025-08-10 20:31:40 WEST; 1 month 12 days ago
Main PID: 57749 (krunner)
Tasks: 37 (limit: 17782)
Memory: 64.6M (peak: 1.4G swap: 338.2M swap peak: 679.8M zswap: 12.4M)
CPU: 2h 58.702s
CGroup: /user.slice/user-1000.slice/user@1000.service/background.slice/plasma-krunner.service
└─57749 /usr/bin/krunner
It seems to me I feel how it was less on the first invocation.
Or after a while without interaction bloated RAM get swapped out and launcher invocation need to fetch swapped out info.
For comparison here is how krunner looks on my current machine. After some time without interactions:
It seems to me I feel how it was less on the first invocation.