I usually ignore Cup. That's a solution. On another angle, you may accept Cup as a super difficult challenge.

My teams usually are knocked out in early rounds. But my L17 team surprisingly reached the final in this season. Other top 8 teams are a level above mine, but luckily they are not too strong. The opponent in coming match is about 3 quality points above my team. It is a clear difference but my team may still compete.