Necessary work?

Brake fluid replacement interval is 3 years in the maintenance booklet, so you're on borrowed time. Used to be 4 years in the booklet, until Toyota had recalls related to master cylinder seal failures, then the interval was shortened to 3 years around 2012.

Total power steering fluid volume in your truck is small, like half a quart. That half a quart gets continuously churned and heated when you drive. 5 years is a good interval. Though you can probably wait until your steering rack leaks and just flush the fluid as part of the $1500 rack replacement job.