You can enjoy kayaking in the PNW year round without a dry suit. Lots of people do. Lots of people also paddle board and kayak without a PFD.
Neither is smart. In addition to water temps being cold year round I've noticed that the wind predictions tend to be less reliable in winter. The only time I've had to do a rescue was a ~50 yards Alki point in winter. The wind report underestimated the gusts by about 5-10 mph.
Someone died last year in a popular local kayak spot. He was wearing a PFD and still died from hypothermia. https://www.heraldnet.com/news/death-of-everett-kayaker-puts-safety-top-of-mind/
Kayakers have died in Green Lake and Lake Washington in winter due to the water temps.
The book Sea Kayaker Deep Trouble was written by a local kayak expert. https://www.amazon.com/Sea-Kayakers-Deep-Trouble-Magazine/dp/0070084998. That can tell you about how stuff goes wrong in our local waters, although it has stories from all over.
I've seen cold water shock happen in real life. I was a kid kayaking with my family in Lake Union in Spring. My dad's boat caught a wake side-on and went over. Despite a pleasure boat responding immediately and harbor patrol being there within 10 minutes my dad couldn't help with his own rescue. His muscles had seized up and he physically couldn't do anything more than hold on to the swim ladder on the pleasure boat. He and mom learned to canoe and kayak in Wisconsin. They thought they understood cold water danger. That day they realized that it is actually different here.