Sortie requires a static/group of players if done seriously, it is fairly difficult, has a time limit and allows players to access it 7 times a week.

This means players can burn out, or the static can fall apart due to 1-2 members not being able to do runs 7 times a week (while everyone else wants to) and this causes friction and stress.

If you allowed players to do Sortie 3-4 times a week, and increased the rewards so that they get the same reward for less work it would be far less stressful, would ease congestion and players could enjoy it more.

Sortie is good but you're allowing players to do it too much and they are burning themselves out, or their statics are breaking apart.