Apple released two MacBook Airs in 2020: a 13" Intel-based model, and a 13" Apple Silicon (M1)-based model.
Apple no longer has any Intel-based Macs in their new Mac lineup – and the current version of macOS (Sequoia) won't run on any MacBook Air introduced before 2020. Apple doesn't tell us their plans in advance, but I'd guess that there is a good chance that the 2020 Intel MacBook Air won't get many updates after Sequoia – if it gets any future major version updates at all.
Even the M1 MacBook Air does not strike me as a great buy at this point – given the improvements to be found in the M2 MacBook Airs, the M3 MacBook Airs, and 14" MacBook Pros with plain M4 chips.
- M2 MacBook Airs offered a choice of 13" and 15" screen sizes, could be ordered with 24 GB of RAM, had better sound systems than M1 MacBook Airs, and added a MagSafe 3 charging port that could take some pressure off the two multi-purpose USB-C (USB, USB4, DIsplayPort, Thunderbolt, Charging) expansion ports.
- M3 MacBook Airs added the ability to drive one external display with the lid open (same as the earlier MacBook Airs), two (with limitations on the second one) with the lid closed.
- 14" MacBook Pros with plain M4 chips can have up to 32 GB of RAM and can drive two external displays with the lid open. They also have a third multi-purpose USB-C port, a HDMI port, a SDXC card slot, and a miniLED-backlit display with support for playing HDR video content.
There aren't any M4 MacBook Airs (yet).
I would suggest getting at least 16 GB of RAM on whatever notebook you buy. Although Apple now includes 16 GB or more of RAM on all new Macs, some of these Macs shipped in versions with 8 GB of RAM, and there may still be 8 GB models in sales channels. RAM and internal SSD storage are not expandable on any of these machines; what you get at order time is what the machine will have forever.