No GPIOs, no I2C, no SPI. If you are purely in search for a small light seever, this is a suitable choice, but Raspis are popular also for the more unusual (for consumer/office devices) IO.
Good you could add a serial comnection to a microcontroller etc, but then the solution won't be as elegant.
Sorry I don't really understand the question, but:
- if you ask whether the way of using GPIOs on a Raspi is elegant, I would say, yeah quite. Python and gpiozero are a good elegant way to go that route
- if you ask whether it is elegant to use GPIO on a Raspi in principle, I can't answer your question because that depends on what you use it for. There are extremely elegant ways and there are ugly hacks that shouldn't exist.
That being said if you quickly need analog input you can just add an ADC to the gpio and you have it. That is more elegant than having to add an usb peripheral.
Good you could add a serial comnection to a microcontroller etc, but then the solution won't be as elegant.