I've owned boats for over 40 years and never come close to flipping one or fallen off any. I've worked as a marine rescue volunteer as well as worked comercialy on many different vessels. I don't think the basic safety kit we have to have onboard over here is anything extreme even though I've never had to use any of it, I've also never had an engine failure that has resulted in me not getting back under my own steam. Smoke flares can be very hard to spot in windy conditions when the smoke gets blown close to the surface, 1-2 miles in windy conditions.
If you've got half an ounce of common sense you won't get into trouble. Check weather forecasts, maintain your engine by reputable mechanics, monitor the vhf radio and you should never need to use any of those items we carry as insurance against the slim chance something goes wrong.
I put my boats through seas I had never experienced back in the UK and that includes working on trawlers and a French potting boat. Here We freedive in surf conditions around offshore reef which lobsters hold on and often get wetsuits torn and masks ripped from our faces as we wash over barnacle covered rocks. All this talk of holding a plb untill rescue in any sort of rough see is utter nonsense for more than a few minutes. If a boat does go over chances are the conditions are going to be full on herific for anyone not used to being in the water when it's rough.
Just try it from the comfort of your chair, hold onto to something with your one arm like the side of the boat you don't want to get swept away from ( or a buddy or two) then hold the other arm up as if you are trying to keep your plb above the foaming white water. In the water you may be getting thrown about by the sea, certainly wet and cold and maybe even injured. Buy the right tools for the job and stay safe.