Dependencies are not scanned for in libraries

[Semnodime]

TLDR
If my main.cpp has the line #include <Wire.h>, then Wire is added to the dependency graph.
If not, then a library fails to build, despite its header having this line as well.

I created a new PlatformIO project for the sparkfun_promicro16 and copied the lib_deps list from the platformio.ini of an old project.

lib_deps = 
	adafruit/Adafruit GFX Library@^1.11.5
	adafruit/Adafruit BusIO@^1.14.1
	adafruit/Adafruit ILI9341@^1.5.12
	moononournation/GFX Library for Arduino@^1.3.1
	git+https://github.com/adafruit/Adafruit_SSD1306

The new project has only the boilerplate code and thus does not reference any libraries yet.

Error
Though, when I build the project, I get error messages, detailing that the file Wire.h cannot be found (fatal error: Wire.h: No such file or directory).

Workaround
If I add #include <Wire.h> to the main.cpp (although it is not used in it!), it will also be added to the Dependency Graph and building the libary will succeed.

Compiling .pio/build/sparkfun_promicro16/lib450/Adafruit BusIO/Adafruit_SPIDevice.cpp.o
In file included from .pio/libdeps/sparkfun_promicro16/Adafruit BusIO/Adafruit_BusIO_Register.h:9:0,
                 from .pio/libdeps/sparkfun_promicro16/Adafruit BusIO/Adafruit_BusIO_Register.cpp:1:
.pio/libdeps/sparkfun_promicro16/Adafruit BusIO/Adafruit_I2CDevice.h:5:10: fatal error: Wire.h: No such file or directory