I guess it all depends on what you consider the useful life of the computer. All of my kids went through college with base MBA without any problems whatsoever. They continued to use them for two or three years afterwards. The OP's requirements: MS Office plus media consumption can easily be done on a 7 y.o. base MBA model.Get the max 24 GB RAM for sure. Mass storage should be about 2x your needs to idealize SSD operation. SSD can be added externally but RAM cannot.
RAM needs have always increased constantly, and Apple's offering of 96 GB in the MBPs gives us an idea where Apple expects RAM demands to go over the life cycle of a new box. 24 GB of RAM is not some huge amount; I put 4x that in my M2 MBP.
Many folks will be "happy with the base model" today, but we configure a new box for the life cycle of the box, not for today. Apple's Mac OS will allow base model RAM to function, but at some point it will likely be sub-optimal. Spending $1k on a computer and intentionally configuring it to be sub-optimal in the future makes no sense to me unless one plans a really short life cycle for some reason.
Tripling the RAM and doubling the storage will add about $600 to a $1,299 base 15in MBA. Not sure if that is warranted for such basic user requirements.
Edit: Also, base models tend to go on sale with deeper discounts than upgraded models, so the price difference might be more substantial if you are willing to wait for a good deal.