Until I experienced it on my old XA2+ I expected, that SFOS should be by far snappier than Android, since Android’s Java layer slows down execution. However, it turns out that it’s just the other way round. I cannot say what slows down execution of Apps in SFOS.
Beyond any explanation: /e/OS (Android) runs much smoother on my (old) phone.
I wish it was the other way round.