The "hire much more eagerly part" is actually great. Sure, your job can be reduced at any time, but the alternative is to not have the job at all - the business will likely not risk job creation on an uncertain project knowing they will not be able to fire if the project goes south.
In practice, just see unemployment numbers - around 3% in US and around 9% in France, with chronic low-intensity rebellion (yellow vests) happening in the country.
> Employers hire much more eagerly knowing that, if the tides turn, the extra employees will not be a burden
This doesn't sound great for employees (i.e. the majority of the country).