Long read, but I found it very interesting.
You'll most likely peak around 50, then performance will just decline. Be aware that this is a thing. Don't get caught off guard. Don't try to fruitlessly extend your peak. Be flexible, and have a plan to adapt. For example, teaching (coaching/mentoring) is a skill that peaks much, MUCH later in life.
My exit plan is to just retire, or perhaps become a full time mentor or coach or something like that if I want to keep working. I have about 20 years to think about it, but I'm glad I read this now, with lots of time to think about an exit plan.