you've got a number of problems here which is a shame as i can clearly see a lot of effort has gone into this.
#Heart of Atlantis 0104-8741-3064
heavy rivet
firstly, the draon flying feature is a moot point and is largely unused for 90% of the game. They're also not "pets" as you describe so that is misleading click-bait and should be removed since the dragons just appear and do a looping animation when you activate the auto-gathering nodes. The 4 sound tracks are being done via a hand-he;d device which don't loop and everyone shares the same soundtrack and can change it thereby causing disputes over what to listen to
progression is not very rewarding, as a great deal of what you spend currency on is purely cosmetic and serves no purpose. you also have some horrendous performance issues as soon as you arrive in Atlantis with frame rates that fall to below 30fps and this happens a few times on the ocean as well meaning I had to change my settings from Epic to High just to avoid getting a headache
you also have an issue with a post-processing effect which utterly breaks the game. I dunno what causes it but eventually, if players are not together in Atlantis this will happen.
for a tycoon game, there is also no progression being saved other than inventory so if you crash or leave you have to start all over again. because it's also just one environment if anyone joins then they have very little to do if someone has built everything out. During my play through I saw two players join and quit after 5 mins out of boredom.
this also had an unexpected consequence as you have loop dropping turned on so every time someone left they dropped all of the resources they never spent which instantly gave me tens of thousands of materials thereby negating any need to engage with building mines and such. So i'd recommend disabling loot drops and also turning off the main Fortnite UI elements as they're completely unnecessary aside from the hotkeys and create a very cluttered screen.
between all these issues I'd sugegst making it a single player game and not calling it a tycoon because players will get annoyed if they think all their hard work is being wiped should they leave and come back
all in all though, it's visually quite polished but the gameplay and progression needs to be gutted and reworked from the start for all the reasons mentioned above
I'd actually suggest tweaking this into possibly a adventure puzzler game not unlike Legend of Zelda or a Metroidvania where the gameplay loop is build > solve puzzle > build so that there's some sense of "what will happen next" that drives players forwards and they know that every bit of effort to progress will lead to more entertainment. So don't bother with the 1000diamonds to build a wall nonsense.
heavy rivet
something that may work if you wanted to really focus on the "pet" aspect and still maintain the tycoon element, but would require significant map changes, is to use those farming systems to raise dragons that they themselves produce eggs that you crack open for the gemstones used to rebuild Atalantis.
the rebuilding process itself would also give you access to atlantian crops that boost dragon production so that every upgrade gives exponential progression. this would also help to address the performance issues in the Atlantis region since you wouldn't need the mines or much of the buildings as you'd just be reconstructing the main building
the dragons could therefore get bigger to show their upgrade level, or you do a material swap to make them change appearence. add VFX to make them more fancy. give the impression that they really are a virtual pet that you're raising
this method could be expanded to a per player plot with their own dragons but that would require some significant work
but atlantis itself wouldn't have per player progression
fringe cargo
That is the best feedback Ive seen, the fact that you took time to respond to this in depth is great. I will take some of the suggestions and bring it back to the drawing board.