One of our candidates turned out to be a nice guy but extremely lazy and entitled
Not only do you have to do the hard work that 20 people used to do before the pandemic lay offs
Is the guy properly lazy, or is he just not willing to handle the workload of 20 people? I'm a hard worker, but only up to a certain point. If I joined a small team that had one employee trying to handle the work that used to be split between 20 employees, I wouldn't exactly be inspired to go above and beyond my post/pay grade; I'd be concerned that no amount of extra effort I put in would ultimately matter because the team is fundamentally understaffed.

I think you and OP are viewing the problem differently.
I think you're saying "Don't worry about it when they ghost you", which is fine. I agree with that sentiment. I don't worry about it when companies ghost me.
OP, however, is saying a company's tendency to ghost applicants can be wielded against them to discourage the practice. By crowdsourcing information about which companies put in the minimal effort to send out a simple rejection message, some pressure may be exerted on companies that fail to do so. Looking bad on Glassdoor/Yelp/whatever can lead to some companies deciding to change their practices. Not because the company suddenly wants to do the right thing, but because they are now being publicly shamed for their bad behavior. And that could affect their bottom line