The main reason why is for what you are experiencing, and to keep the taskbar cleaned up more without multiple open window buttons for the same program. You can select the multiple opened windows for that icon from the thumbnail preview instead.
About the only other thing you can do is to drag the icons that you use less frequently to the far left to minimize them being moved. When you open a icon to the left of another one, it will move the right one over.
My Computer
At a glance
64-bit Windows 11 Pro for WorkstationsIntel i7-8700K OC'd to 5 GHz64 GB (4x16GB) G.SKILL TridentZ RGB DDR4 3600...ASUS ROG-STRIX-GTX1080TI-O11G-GAMING
Computer type
PC/Desktop
Computer Manufacturer/Model Number
Self built custom
OS
64-bit Windows 11 Pro for Workstations
CPU
Intel i7-8700K OC'd to 5 GHz
Motherboard
ASUS ROG Maximus XI Formula Z390
Memory
64 GB (4x16GB) G.SKILL TridentZ RGB DDR4 3600 MHz
Graphics Card(s)
ASUS ROG-STRIX-GTX1080TI-O11G-GAMING
Sound Card
Integrated
Monitor(s) Displays
2 x Samsung Odyssey G7 27"
Screen Resolution
2560x1440
Hard Drives
1TB Samsung 990 PRO M.2,
4TB Samsung 990 PRO PRO M.2,
TerraMaster F8 SSD Plus NAS
PSU
Seasonic Prime Titanium 850W
Case
Thermaltake Core P3
Cooling
Corsair Hydro H115i
Keyboard
Logitech wireless K800
Mouse
Logitech MX Master 4
Internet Speed
2 Gb/s Download and 100 Mb/s Upload
Antivirus
Malwarebyte Anti-Malware Premium
Browser
Google Chrome
Other Info
Logitech Z625 speaker system,
Logitech BRIO 4K Pro webcam,
HP Color LaserJet Pro MFP M477fdn,
APC SMART-UPS RT 1000 XL - SURT1000XLI,
Galaxy S23 Plus phone