Obviously people would mow lawns but the price would be higher because they don't have to. If you wanted someone to mow your lawn, you would probably need extra income. Or, since you have more free time, you can now mow it yourself and enjoy it instead of feeling like it's cutting into your only spare 48 hours.
The attractive part of basic income for me is that everyone has enough to buy food and housing, so suddenly menial laborers have an iota of bargaining power.
