Let's look at DPR using the example of my Level 8 monk. Subclass Mercy, Dex 19, Wis 16, grapple feat, relevant magic items are wraps +1 and eldritch claw tattoos (+1; can activate for an additional 1d6 damage/attack once per long rest).
So if they are attacking an apponent that they can grapple (say, a Rakshasa, since she just fought one - AC 17, 221 HP), then her DPR is pretty scary if she wants to go all out. +9 to hit (+4 dex, +2 magic items, +3 proficiency), so a starting 60% hit rate. BUT every round, assuming she hits at least once, the target is automatically grappled unless unless it makes a DC 15 saving throw (Rakshasa will save on a 12+, so assume it will be grappled 55% of the time, giving my monk advantage on attacks. With advantange, that hit rate goes to 86% if my head math is correct, so overall we are looking at roughly a 75% hit rate.
Base damage is 4.5 (fist )+3.5 (tattoo) +4 (dex) +2 items): 14 x 4 (attack+flurry) =56 x .75 = 42, + 8 (hand of harm), or 50 damage per round. Plus the Rak has the poisoned condition the whole time.
TLDR: 5.5e has really increased martial DPR.