I have a Samsung A71. It permanently lives in its protective case which gives it good bumpers around the easily-breakable edge-to-edge screen. It’s now 4 years old and has survived numerous tumbles and drops over the years.
Occasionally I have to swap the SD card in it and I am always astonished at how thin and light and fragile it is when not in the case.
I would quite happily have an actual similar size phone to what “I have now” if the battery size was bumped up another 50 percent.
You’re blaming the wrong thing again. Newer phones have higher capacity batteries than the old bricks by far. The issue is the screen, SoC, and modem power consumption has gone up too.
In the phone world, the jump in capacity that modern phones have from my 4370mAh battery in my A71 is negligible. They haven’t increased power density much because that way leads to fires and lawsuits when users bend or otherwise damage their ridiculously fragile phones
My point was, if modern phones had the physical space that my phone + case has, they could have a bigger battery, and that bigger battery would then power all the hungry, hungry electronics.