Why connected two I2C SCL and SDA together?

Hardware Nano Family Nano Every
1

From the nano every schematic, pin 36/37 and 46/47 both connected to A4SDA/A5SCL.
But from the ATMEGA4809, pin 36/37 and 46/47 are for two I2C bus, and also pin 12/13, while the 12/13 and 36/37 are marked with note
"Alternate pin positions. For selecting the alternate positions, refer to the PORTMUX documentation"
It seems we can write the TWISPIROUTEA register to select default TWI0 and SPI0

My question is why on nano every those pins are connected on the board? what do we gain from that? More driving power?

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2

I would imagine it's so that the pins can be used either for I2C or as analog inputs (without having to reconfigure pin functions), as on the 328P Nano.

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3

You can configure the PORTMUX to make I2C bus occur on different pin pairs.

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