With a means-tested UBI, there's more than just yearly earnings to take into account. Depending on where someone lives, they're affected by the cost of their home and the taxes they have to pay. For people living in more rural areas, it's possible to live on $50,000, while the same income while living in a city would struggle to make ends meet.
This questions who would be considered wealthy and who would need aid. Another issue is if this money is contributing to reducing poverty. Unfortunately, humans are unpredictable and don't always make the best choices. What will people do when they find themselves with virtually 'free money?'
In theory, UBI is a fantastic policy, but implementing it is the struggle. Most importantly, a democratic process needs to take place to approve such an approach.
Voters need to examine the potential pitfalls of the system before its implementation.