The human brain has a natural upper limit in how many times it's beliefs can update per year. If the Total new features shipped by every company in the land, every year exceeds that limit, most of it is a gigantic waste.
Large, cash rich companies beyond a point attract opportunists. And soon they outnumber innovators.
After that happens we get run away Involution (change without purpose).
There is never ending amount of work going on, hyper specialization, elon/trump style self glorification/back patting, and all happening with very little purpose or meaning being produced.
The solution is well known. Orgs which have purpose are tuned into the Limits baked into the system.
You can individually turn off 1) voice activation phrases, 2) press and hold side button, and 3) double tap bottom edge to type
For the flashlight, I assume you're talking about on the lock screen. You can customize the lock screen and remove that button entirely. If he has a newer iPhone, flashlight is probably a good use for the "Action Button" on the left, if he doesn't want to use that for toggling ringer/vibrate.
This should be possible? Or at-least it was when I was still using an iPhone, which was less than a year ago.
1. Search settings for Apple Pay
2. Tap Apple Pay Defaults
3. Toggle off Double-Click Side Button
(Siri disable instructions in sibling)