4GB in my 2011 MBP worked fine for the first 10 years of it’s life, even with iMovie. Yes, there were bigger models available at the time, but future proofing wasn’t a thing back then, I’m not so sure it needs to be now. The only real reason I upgraded the 2011 to 16GB myself was just to see if it would work. It did, but to be honest I didn’t notice any significant performance improvment for the €70 I paid for the new RAM.
Basically, I think the MBA M1 works perfectly fine with 8. If you genuinely need 16, you may be better served with a MBP. The way I see it, the 13” M1 Air is Apple’s new entry level laptop for home/sofa/student/cafe use. That they even offer it with 16 seems pretty pointless, to me.
It's a bit like ISP's offering you 1Gbps internet speeds when the vast majority of us just don't need it. Wow, I can now watch a full length movie in under 2 minutes! Right now in Belgium the slowest uncapped plan I can find is 4G @30Mbps for €40/month and it works perfectly for what we need it for. My wife and I can both watch Netflix in HD at the same time on separate laptops, while downloading updates in the background. An uncapped fibre line at 1Gbps will cost €58. Sure, I have that money, but, keep doing things like that and by the end of the year you have wasted thousands of Euros. Ok, even with ISP contracts you can weasel your way out, but with laptops you are stuck with them. However, Apple products tend to hold their value, if you look after them. So if after a few years you now realise 8 just isn't enough, you can always trade it in or sell it on eBay. But until then, I like to come in low.