Turrets are in a rather precarious spot. They do significantly less damage, are bound to a tracking speed, are easily countered by chaff and suffer from jitter. On top of that come ship specific problems. Some ships can not make use of fixed weapons because of the placement of the hardpoints, for example, which makes a ship with a clustered weapon placement inherently better than a ship that has the weapons more spread out.
The lower damage is not inherently a drawback, however, as that is needed to balance the lower power draw, which is needed for a weapon that sees more sustained action. From my observations, the lower power draw is not consistent though - some turrets draw more than fixed, some seem to draw less.
What makes turrets bad is the lack of specialisation/options to improve their benefits or strengths. No experimental to reduce jitter? No tracking computer mod that allows turrets to automatically target and shoot at missiles and rockets? No option to improve tracking speed? No mod that switches from heat tracking to visual tracking, radar tracking or other tracking methods? There isn't even a tracking experimental that allows turrets to anticipate where a target will enter their field of fire - they go back to their default position instead. If a top mounted turret tracks a target going past the ship, a bottom mounted turret should swing around with a rough anticipation where that target is coming in once it leaves the field of fire of the top mounted turret, but nope.
There is a ton of options that is flat out untapped.
The worst aspect, to me, is the need for turrets/gimballs to compensate for bad weapon placement. The Type 10 is a really good example for this - as it has loads of weapon hardpoints but they are so spread out, that only 3 or maybe 4 of them can fire at a target with fixed and even with gimballs/turrets it is not guaranteed that most of the weapons point at a target up front. This means that a ship with a better weapon placement can do the same damage with 30 to 80 % of the weapons.
While there is a point to be made for play balance, there is also a point to be made for fringe cases, that require turrets/gimballs. This can create a deeply unsatisfying mode of play. There is nothing wrong with pushing players to utilize turrets and gimballs to compensate for playstyle or a ships inherent weaknesses. It does become a problem when the tools to make those compensations are lacking.