I have a beast of a pc: intel i7, 32gb ram, nvidia gtx4070 with 16gb vram. All settings ingame are maxed. So IF it is hardware related than I wonder what kind of hardware you need.
Also if it is hardware related how do you explain that st. Maarten, Saba and St. Barth are excellent and the rest is mediocore? You mentioned a phone? Perhaps my mistake but I always thought that aerofly fs 4 was a pc simulator and also for steam deck. Don't get me wrong I love this simulator especially in VR. Before anyone gets any ideas: the review was done without VR. I use the meta quest 2, also with max settings.
I have been using this simulator since the original simulator which was limited to Switzerland. I am a fan. So do not attack me because I am critical in this review.