You obviously don't know how Android works. When an app hasn't been open for a while and it has no background tasks, it gets put to sleep. Waking it up takes a second.

You can delay that by selecting the app in the settings and choosing its Battery setting to Unrestricted, however, despite its name, it will still get suspended

The checks are poorly coded. Even on Unrestricted, if you play music from a web player, the browser will get suspended after the song ends but before a new one starts playing because there's a point where it awaits data on the foreground task, Android sees it has no background tasks and suspends it.

Man, I backported freezer v2 cgroup implementation into 4.4 kernel so these cached tasks are suspended, don't tell me how Android works please :)