Spring weight.
I call it "weight to horsepower". You have a smaller gun and in this case a smaller and lighter gun, firing a cartridge with certain ballistics. So the spring has to among things "protect the gun". Hypothetically if the same gun was designed to fire a .22 lr or .25 ACP, it would be easier to retract.
Hence one of the big reasons many ladies, and those with physical problems do not use small center-fire pocket guns, they can't retract the slide, the recoil ( weight to horsepower again) hurts and make it very hard to hit anything. Oh - this also means they never practice.
Now granted the Beretta Jetfire is only a .25ACP, the tip up bbl means one does not have to retract the slide - making it easier to load and make safe. The slide is easier on the Jetfire, trigger pull is SA and very good. Similar features for the Bobcat , available in .22lr ( affords lots of practice due to inexpensive ammo) and in . 25ACP. The best kept secret - tho pricey is the Beretta .380 which is a beautiful gun, easy to shoot , easy to load and make safe with tip -up bbl feature as well.
Medium frame revolvers like a model 10 , are very popular for a reason with the ladies and those with arthitis, physical problems. 148 gr target wadcutters are easy to shoot, accurate and will do defense if need. OLder police trade ins are snapped up in a hurry for a reason.