Unemployment isn't forever and the additional $600/week is only for the current pandemic situation and expires as of July 31. This is not a windfall for those who are now suddenly without a job.
But more importantly, someone who has just been laid off has close to zero employment options right now. They might be able to find a short-term job at a grocery store or Amazon but if they're over 50 or have any sort of health issues that's probably unwise. And even if someone is willing to risk it they're unlikely to get the position anyway, no matter how qualified, because those few positions are absolutely flooded with applicants[1].
There cannot be a "perverse incentive" (or any incentive at all) to stay home and collect unemployment when that is a person's one and only option.
[1] https://abc13.com/heb-who's-hiring-houston-jobs-covid-19/606...
The economy isn't all-or-nothing. This situation is bad, but it's an exaggeration to suggest that no one is hiring.
The perverse incentive comes into play when people start turning down $20/hr jobs because they're making $23/hr on unemployment insurance. They'll want to go back to work eventually, yes, but they won't rush into it will literally cost them money to do so.
I'm not suggesting that unemployment insurance is comfortable or ideal, but I think it's important that we avoid situations where people must deliberately choose to reduce their income to return to work.
This is not a time to be talking about bootstraps.
You're being downvoted because you overgeneralized ("many places"), but this is actually true in some scenarios.
See "Unemployed workers could get more than 100% of their paycheck under the coronavirus bill" https://www.cnbc.com/2020/03/27/how-unemployed-workers-could...
It's a perverse incentive to getting people back to work, so I expect this loophole will be closed soon.