Complex sentence: Giving those warnings is not only educational or dissuasive, it is necessary otherwise administrators would be further burdened with block requests against users who would not have persisted in their disruption anyway, and could not focus on the severe or persistent ones.
Split into simpler sentences: Giving those warnings is not only educational or dissuasive, it is necessary. Otherwise, administrators would be further burdened with block requests against users who would not have persisted in their disruption anyway and cannot focus on the more severe or persistent ones.