Earlier quoted context omitted.
How do you know that, and how do you explain that more people get on welfare as it gets available to them, even though they have good employment options? Moreover, why does that matter at all - how is it fair to those still working, who are forced to pay for those who don't want to? I'm all for welfare - helping people in need. But I'm not going to fund someone's lifestyle.
To take a market perspective to this: I think there are some costs that people fail to accommodate for when comparing employment vs welfare. We used to consider homemaking an actual profession, because... it really is. Now that we are expecting households to have dual incomes, we are recognizing that income on paper, when in reality it always was there, it just was not formally recognized. With the cost of childcare…
But I disagree with your comment on the second point. As I said, I'm all for welfare/assistance given generously to those in need, but that's different from funding non-working lifestyle of those who have good working options and simply don't want to work.
Some part of UBI might overlap with the welfare part, but it's going to significantly increase the number of people who don't work just because - and it's not fair to fund that from the money made by those who work, and especially not fair to take it from those who must work because UBI is not enough in their situation.
UBI could be funded from sources like sovereign funds - why not. But let's not take money from people who need it just so a group of people can quit their job. Classic welfare at least says that those who receive it need it more that the person that pays.