If we assume that the financial sector is good for society, then a productive element of it is idling causing inefficiencies leading to higher fees.
If the assumption is incorrect, then the financial sector is not a productive part of the economy. In this case the worker's vacation is irrelevant since it's just a manifestation of the parasitical nature of it.
Either way normal people are paying for this civilized system's largesse.
The truth is somewhere in between. The role of the financial sector is to match capital with projects needing capital needs. Since the 80s (?) this is an insignificantly small portion of modern finance - most of it is parasitical sloshing of funds around to either gather fees or launder money.
If the answer is no, then you should reconsider thinking that garden leave is bad. It’s essentially a buffer that covers the switching cost for agents needing to decide which principal they work for.
If you removed garden leave you’d have a higher up front cost for rational actors who needed to account for the fact that they could lose their income stream at any moment if they were fired
Remove non-competes, then there's no need for garden leave.
If an industry insists it needs non-competes, the dept. of labor could issue exceptions with strong penalties (x3 wages (incld. expected bonuses) for the duration of the non/ -compete, etc)
[1] an argument could be made that the more workers are put on garden leave the better it is for the economy, vis a vis less folks doing damage. Overall, I think the whole fintech industry is a waste of STEM talent. Those physics PhDs could be something beneficial instead, like being a magician at three year old birthday parties.
Sounds like a great incentive to quit the job and hang out for the duration of the non-compete. If I can make more money by working than not working, I know what I'm doing.