I'll start by saying that mesmer was the first class I played. I've loved it for almost 5 years now. I enjoy tier 4 fractals and the occasional CM. I loved last year when they made chrono a one stop shop for all boons. This was great, because the main function of chronomancer in fractals is group support with a focus on maintaining alacrity and quickness. Adding every other boon was a nice perk. It made carrying bad fractal groups possible and made T4/CM even easier. It definitely needed a nerf. However, the current situation has made it all but useless to PUG (Pick up group - random people who join via LFG) fractals. It's still perfectly fine for static groups and groups who fully understand not only fractal mechanics, but also group content mechanics. But it is unable to maintain alacrity on people who don't understand that Guild Wars has designed group mechanics around a 600 range, or people who are still learning fractal mechanics and are unable to stay within boon application range.
Here's why. There are now only two things a mesmer can do to apply quickness: Tides of Time or Well of Recall. Both require predicting where the group will be several seconds after casting a skill. The Tides of Time shield skill now only applies quickness on the outbound journey. If no object obstructs it, or it does not fall off a ledge, it applies alacrity on the return trip. Basically, you have to plan for where players will be between 0 and 3 seconds after casting, based on terrain. Well of Recall is even more restrictive in target area than ToT and requires you to predict where your group will be standing 3 seconds after you cast it (it does a chill effect to enemies for the first three seconds, then applies quickness to anyone standing in the well). Those are the only two ways to apply alacrity to other players in your group (with chrono). With the 2018dec05 patch, Signet of Inspiration now extends the duration of boons on other players, which is fine if you are able to initially apply a boon to a player.
In groups of players which are still learning group content mechanics (particularly T1/T2 fractals), you frequently run into players who do not understand how Anet has programmed group content. Class buffs (like Spotter and Empower Allies) only work to a range of 600 units from the source player. Also, class skills (like Banner of Strength or Sun Spirit/Frost Spirit) only have a range of 600. Some have even more restrictive range (like Renegade's Order's from Above, range 240), but for the most part it is safe to say that group content is based around a range of 600 units. It's easy for new players to not understand this since there is virtually no range indication User Interface and anet has subversively programmed some skills to function better at ranges over 600 units (Long Range Shot, Spatial Surge, and DH Longbow using Pure of Sight to name a few). That combined with the natural thought pattern, "the further away I am, the less danger I am in" leads inexperienced players to intentionally move away from the group / target enemy. Then the basic game mechanics like knockback or immobilize with a mobile enemy works to split up the group. Then fractal specific mechanics (generally ground targeted attacks) split the group (most players have learned to avoid red rings and such). Then fractal instabilities split the group even further (I'm looking at you, new awful Social Awkwardness). The net result has been, in five months, when playing with inexperience players I have been lucky to give more than 1 other player more than one stack of alacrity which lasts for less than ten seconds.
Bottom line: chronomancer cannot give its class-specific boon out. Which is absolutely ridiculous. You can maintain quickness several ways. Easiest being to use Superior Rune of the Chronomancer. But there is no extra trait you can use, nor equipment you can swap out which will make it possible to give out the primary reason your specialization exists. As such, I retired my mesmer until it is useful as support again. Which is sad, because I really liked playing mesmer. Also, Renegade lacks the npc control that mesmer has with Temporal Curtain/Into the Void. (FB could replace this functionality if the radius of Heated Rebuke were larger. TC range 600, HB range 240).
I would love it if the next balance patch addressed the problem of chronomancer being unable to apply alacrity. Changing the initial function of Tides of Time & Well of Recall to be alacrity application could work, or adding a rune that does something to apply alacrity (heck, change Superior Sigil of Water to apply alacrity instead of healing and you unlock it from class restriction), make SoI apply alacrity if you have it... there's a number of options. But as is, chrono is only useful to neckbeard groups and T4 listings requiring 100 Essence, Leaves No Hero Behind, and full legendary armor.