Ram speed confusion

Ok so I'm fairly new the whole PC community but I've had my build for the last maybe 6 months. Specs as followed, rtx 4060 ti 8gb, Intel I5-13400f, ASRock b660 m-c, 16gb ddr4 thermaltake toughram 3600 18-22-22-42. So I was noticing when playing games I was using pretty much the entire 16gb of ram, sitting between 90-99% constantly when running any of the games I play. I decided I was going to upgrade to 32gb, instead of buying an additional 16 and using 4 slots I got a kit on Amazon that was 2x16gb Gskill trident z neo 3600 16-19-19-39. I cleaned my whole system out and installed the new ram last night. So immediately when booting up Hogwarts legacy as well as Witcher 3 I noticed my load times were significantly faster. When I say significant I mean 5-6x faster than before! An absolute huge amount I was not expecting from that small upgrade. I spent a month researching brands and speeds and the capabilities my PC could even handle, I went with this specific kit because the latency numbers were slightly lower and from what I read that was the best choice. So I guess my question is this, was my old ram faulty in some way? How could such a slight difference in speeds on paper result in such a huge improvement? It's running at the same mhz same xmp profile I changed nothing in my bios all I did was install the new ram and bam! Just like that load speeds seriously feel like I'm using a whole new computer. I never really considered my PC to be slow in any way I mainly upgraded out of want not need, atleast that's what I thought. Could such slightly different latency rating make that huge of a difference? I'm also noticing less stuttering in cut scenes and just overall better performance out of my rig now. Overall I'm extremely pleased with my choice but just wanted some opinions from anyone who has a little more knowledge than myself about how big or small of a change that small upgrade should have made. Thanks in advance!