This is the behaviour you want.

Memory pressure shows the amount of memory being compressed. Most of the time it should be green but it goes into red when you are low on memory and not using swap.

Macs make a few calculations to determine when to compress memory vs when to swap it. It's not a simple as %.

Firstly, there's system load. Your Mac will always swap when the CPU is high as it takes extra CPU cycles to decompress from RAM.

Secondly, and this is where I think your difference is coming from; if your using a laptop your Mac will avoid swap so it can turn the SSD off more often, saving power.

Finally, GCD will move paged data and data marked as such in memory to SSD, or use quick compression depending on optimal power draw. That is much more likely with M1's 4 low power cores that can likely decompress as the larger cores read.