I simply find it a bit annoying rather than difficult.

There is a lot of factors that can ruin the melee dps damge such as Tank moving that cause the enemy to move (the side/back effects are missed a lot because of this), constant worry of heavy damage AoE at melee that force you to stop and run, and higher risks when fighting enemies and bosses since they tend to have more dangerous Melee attacks than range attacks.

More things to worry about as a melee dps that Range DPS tend to not have torry since they are mostly out of range for these things.