Like you, I'm not convinced this wouldn't turn into a spiral of lazyness. I would add though, that if this is implemented properly you should always be getting more money with work than without. So even if the taxes rise there should always be an incentive to work.

Currently in Germany for example there are a lot of people on long-term unemployment that have enough children and low demand for their skills that if they worked they would earn less. This in principle is one of the advantages of UBI. That if everybody gets it, you don't have to take it away as soon as somebody earns money. So everything you earn, will be beneficial to you.

Of course if UBI is set too high it might not be attractive to work for only a little more, but right now you have people that would earn less if they worked.