3 meter MagSafe 3 to usb cable?

FWIW, a 3 meter AC extension cord will probably be much cheaper. It does not need to be heavy duty since the Mac draws very little power. A cheap lamp extension cord will be just fine.

As to why Apple does not make a 3-meter cable, you'd have to ask them. They make a 2-meter one in four colors.

USB-C to MagSafe 3 Cable (2 m) - Starlight - Apple

My understanding is that you should have gotten one of these with your M2 MacBook Air.

If you search Amazon for "usb-c charger extension cable", you'll find a number of extension cables which feature a USB-C socket on one end and a USB-C plug on the other.

I don't know whether these are "Apple-approved", but they did seem to be available in lengths ranging from 0.6 feet (0.18 meters) to 2 meters. The USB-C standard would allow vendors to sell cables that only carry USB 2/3 power – which might be OK for a phone, but wouldn't be for a computer. What you would want is an extension cable which supports USB-C Power Delivery and is rated for at least 100 watts (the old Power Delivery standard). If you see just the 100 watt claim, that probably implies Power Delivery.

Here's a 1-meter one that might be promising.

https://www.amazon.com/UGREEN-Extension-Extender-Nintendo-MacBook/dp/B08NTCD6VQ/ref=sr_1_6

The longer the cord, the greater the electrical resistance if the conducting wire gauge is held constant. When any cord gets too long it can act as a resistance space heater. This is bad.

My guess is Apple determined the length they chose because it doesn't increase resistance enough to either attenuate voltage or cause excess heating.

As to longer cords ... caveat emptor

ku4hx wrote:

The longer the cord, the greater the electrical resistance if the conducting wire gauge is held constant.

https://www.howtogeek.com/810652/does-usb-cable-length-affect-charging/

This article does not deal with extension cords specifically, but recommends looking for charging cables that are certified by the USB-IF (USB Implementers Forum) and from a reputable brand. (Especially for longer cables that have lengths of two meters, three meters, or more.)

I came across another thread where someone said that USB-C does not allow charging extension cords, because Power Delivery is defined as "a protocol amongst the source, the sink, and THE cable."

https://www.reddit.com/r/UsbCHardware/comments/rh3fwe/maximum_length_of_a_usbc_gen_2_10_gbps_extension/

So now I'm not sure what to think.

Wow, thanks. After constantly tripping over the short cord, I was looking for a longer charging cord and saw your solution. I have the same adapter from an earlier MacBook and so tried this and it works great.

I use This Adapter for this purpose. (Mine isn't this one, as mine came with my 2016 MacBook Pro, but this one looks identical).