Can someone explain how invasion is supposed to be fun?

I enjoy it. I am on 32/65 (last tier) and have only suffered 2 losses. You really have to be creative with how you play and when to take a hit or cast a spell. I am using Mang, siegebreaker, Flame Troll and Infernus.

Same. After 5-10 battles just had to ā€œovercomeā€ instead of enjoying the process. I don’t even care about rewards anymore, so boring this process had become… same battles over and over and over again while enemy stat numbers growing bigger. Ought to use the same weapon, same team, same approach for each battle. I’m OK with 5-20 similar battles, but when everyone in active guild had to do 200-500 battles so that the guild can collect rewards, that’s way too much.
I think 5 different bosses (along with minions) for each raid, which require different approach for each battle, could be more fun. Delves already represent something like this, but you can’t change your team there.