I doubt the M1 macs are really using memory much more efficiently; the stock M1 macs with 8GB were available rapidly; the Macs with 16GB ram or larger disk space had a three to four week delay when ordering; a lot of enthusiasts and influencers rushed out and got base models; they are then surprised to find they can work ok in most apps with only 8GB.

Perhaps they never really needed to fit 32GB into their intel macs either. Some days after the glowing reviews; and strange comments about magic memory utilization; we now see comments concerned about SSD wear due to swap file usage.

If the applications and data structures are more compact in memory on the arm processors; it should be easy to test; you just need an intel mac; and an M1 mac running the same app on the same document and look at how much memory it uses.