Earlier quoted context omitted.
You are still better off working. You will still get ubi
Haha why not just increase the threshold at which you get taxed? Same end result except no one gets money for doing nothing. Those on low incomes get to keep all their earnings.
For example caring for people who need caring for (elderly, children, disabled) is essential work that is mostly done for free. This is a lot of work collectively.
In a system that properly values essential work it would be paid, but it isn't paid because those needing care cannot pay for it, and other people and "the system" are not willing to.
But even if "the system" started targeting all forms of care work, there are countless other things which are valuable but unpaid. It seems utterly implausible that we would ever devise a system that pays for all work that is valuable, if only because people disagree about what is valuable and all the power dynamics that result in the emergent properties we see as capitalism, "the economy", etc.
In your idea, increasing the tax threshold does not solve this problem or even begin to address it. So it's not an equivalent result.
UBI does address it, by removing the power dynamics and gate-keeping for basic resources, letting people figure out themselves what is the best use of their time in each individual circumstance. The very concept of "what is valuable" gets a refresh, away from the systematic biases that emerge from centralised rule-making, power-law power structures, and the error of conflating money-value with human value when humans do not have evenly distributed access to money with which to signal what they value.
The fact a very large number of people put so much time into tiring unpaid work (such as caring), often on top of their paid jobs (if they have any time left for paid jobs, some don't and it sucks), shows that the "UBI fear" that everyone people would sit around idling their whole lives is very unlikely.
It's likely some people would still call it "doing nothing", as they do currently, but they would be wrong.