I think Machinist has been on a backslide since 5.0, which is really unfortunate.
When Heavensward was teased, I mained BLM - and I was taken with Machinist as a class, aesthetically, so much so that I leveled it from 30 to 50 on Heavensward's launch day so I could start the MSQ as my new main and ever since then it has been my primary role. I truly think the removal of gauss barrel and ammunition robbed the class of its identity and laid the foundation for where it is today.
If they had let Bard remain as the instant DPS but left the casting bar toggling and ammunition in it would have been a foundation to justify giving Machinist a DPS boost similar to Summoner or Red Mage who benefit from being casters, though they are taxed for their raising abilities. But they didn't. and it has been painful and disappointing watching my favorite class slip down. I really think Machinist is Square Enix's red-headed stepchild.
Flamethrower is a key example of this. Why does this ability exist? It has remain unchanged since they pulled the heat generation off of it and it has dipped into irrelevance. What was once a capstone spell is now borderline useless. Full Metal Machinist is a visually interesting spell but it's nothing very different; the class has changed very little and it is consistently being outperformed by even Bard at the higher percentiles.
I have seen Extreme trial PFs eschew Machinist from the ranged DPS slot, leaving only Bard or Dancer as options. I remember this happening before, as well, I think during Shadowbringers. Either Machinist needs to be a selfish DPS and be given a bump to compensate for that or they need to reinforce its utility and bring back Rend Mind, Promotion's mechanics in some other capacity similar to Bard's songs, hell, give me Heartbreak or Lead Shot again.
Reload and Quick Reload's animations were great. Grenado shot as an AoE combo, something. So much of the class' identity in Heavensward was thrown away.