Do we know if the Xbox is doing hardware compression when saving RAM to storage for Quick Resume?
IMHO this is the only reason why the console also supports compression in hardware. I really can't think of another scenario why the console should have such a compression block. Recording gameplay is encoded and not a good case for data compression. So no need there.
Save games are far to small, can be done by the CPU instantly.
Dumping the memory to the SSD, maximizing throughput and saving write cycles on the SSD (and space) is the only think that I can imagine there.
What is really clear with the write speeds of the SSD that the PS5 will never support something like quick resume. ~200mb/s is just not enough for a quick memory dump.
But maybe game developers can do something similar by making a sort of quick save and quick load function. Quick resume so far is ... more like brute forcing such a feature. The quick save/load from the game would be much more elegant but than the developer has much more work to do.