The Ford system I'm referencing is the SecureCode keyless entry system, and is truly keyless entry (with the 5-button keypad, either physical softtouch buttons or capacitive touch buttons) - you simply punch in a combo for true keyless access to the vehicle (no need to have a key with you at all, not fob/transponder-based like the Audi).
This is a fantastic convenient option to be able lock all your valuables inside the vehicle (even the keys to the car can be secured). Personally, I've used this with the family when out at an activity when we're separate from one another and/or I don't want to carry keys with me (like small sailboat racing). They have access to the car and I don't run the risk of (a) losing them in the water or (b) giving them to a kid. Back in the day, I used to leave the car keys behind the fuel filler door. When those became lockable items, I'd hide them behind a tire, or actually IN the backside of a wheel. SecureCode access is a huge upgrade.
Keyless entry into the Roo means kids/guests/people without keys can come and go at their leisure and still maintain some small sense of security that comes with a locked RV. A set of keys to said trailer (and related) can be located inside, so - after opening the door with a combo - anyone can get to a single key (or set of keys).
Your minimalist key ring is set up the way mine USED to be setup (and what I prefer). But circumstances beyond my control forced me to move from two keys and a fob to seven keys and a fob - it's a pain to haul around, and I'd rather not hike with it (and that's not even the master trailer set, which also includes two additional keys for trailer locks, a small flashlight and a mini-tool). I bought a few additional trailer keys, so when I wander from camp, I can just carry one. One is additionally hidden/wired up outside the trailer, just in case.
Keyless entry, while battery operated, is enough of a convenience for some that it's an offered option for many applications, from cars and homes to RVs and trailers. Bonus: if the batteries do die? The lock still accepts a key. Hardly the definition of "high tech" (your tv remote is higher technology). In this case, the "complication" is added convenience and flexibility, and is valued enough that mass producers and marketers design, produce, and sell such systems.
One could ask a similar question: why "complicate" your life by having anything, let alone something as absurdly complicated (and "high tech") as a trailer?
OP sees the benefit and wants the convenience of keyless, combination based access to the trailer. You see the potential issues and see it as an unnecessary complication. If it's truly "YMMV," then why not let it be that way? *shrug* The bed you wake up in must have two curmudgeonly sides.