It's a compromise.
Spread axles WILL impart a LOT more stress on things when turning sharp. That CAN over time cause hangers to fatigue and fail. It won't happen right away, but can take years. That is called metal fatigue.
The advantage is the ability to use a lighter frame, with less tounge weight and a more stable tow with a less capable TV.
Since many people that want TTs do not have a full size truck, the manufacturers are filling a market need. Most of these TTs simply won't be used very hard or often and things will work out fine for them. If this type of TT fits what you need, then it is a good fit for you. If you have a stout TV and tow often then it may not be a good choice for you.