So if I make a significant and lifelong intervention of exercise, I still have 5/6 chance of dying prematurely. No thanks.
There is a bit of a curve to get over with technique, breathing, etc. where you really can’t swim very far and you feel super slow at the start, but if you work on it it you can build up pretty quickly. You burn far more kilojoules in the pool than doing something like running too which is nice! I’m 32 now, been doing the swimming for three years now, and with a bit of diet improvement I’m definitely in the best shape I’ve been in since high school.
I’d definitely recommend it for people who don’t like the feeling of other aerobic exercise like running or cycling.
For $100 and paid a lifetime fitness swim instructor $180 to help me improve, but to no avail. (The videos helped some, the instructor was garbage).
In terms of videos I quite like this channel on YouTube - https://www.youtube.com/@SkillsNT - it's all free content (they make some money with paid intensive camps every now and then at various places around the world but obviously you don't need to do that!). They have a fair bit of stuff about breathing, including exercises to do both in and out of the pool to improve breathing and how your body responds to CO2 in the bloodstream. Those exercises could also potentially help.