Short answer
Couples can protect their relationship by deliberately creating time for conversation, rest, affection and privacy even when daily responsibilities are demanding.
Islamic Guidance
What Islam teaches
Marriage includes companionship, affection and mercy. Islamic family life does not require spouses to neglect each other's reasonable marital needs.
Practical Guidance
What you can consider
Share responsibilities fairly, plan regular couple time and avoid allowing phones and routine tasks to consume every opportunity for private connection.
Sources
Qur'an 30:21; Qur'an 4:19.