iPadOS is a marketing name. The OS that the iPad runs is 10 years old and its "infancy" is less about age and more due to it being treated like caged veal. Its lack of growth is intentional.
We've been saying that for 5 years and the iPad has not matured anywhere near the same rate as the hardware. So a more likely scenario is that the M1 Mac will continue to differentiate itself from the Legacy Mac and the iPad will remain the same.
I think there's been some strides.
1. Fewer websites that don't work in Safari for iPad
2. Access to "On my iPad" storage (granted, not full file system access)
3. Ability to mount network shares
4. File handling (still buggy especially when dealing with large transfers)
5. Addition of mouse and trackpad support
6. Improvements to home screen/dock and some native app layouts to take better advantage of screen real estate
Memory management is still an issue on iOS. Apple needs to add more RAM or use an actual swap file.
It's not like the CPU, GPU, RAM and SSD improvements were for naught. They need that in place first before they can tackle software.
The flash storage on these things used to have random 4K write performance lower or equivalent to HDD. I just ran Jazz Disk Bench on my 512GB Pro 10.5 and it only does 4.3 MB/s, 1090 IOPS and on the 256GB Air 3, it's 8.7 MB/s, 2230 IOPS. Even the 1st gen Intel SATA2 SSDs did 15-20 MB/s 4K writes. I don't know how much that has changed in A12X/Z and A14. Looking at these benchmarks, that plus low entry level storage capacities may be why they haven't implemented swap files in iOS.