While I agree with most of what you wrote, there are already countries where all individuals' tax returns are public https://www.miamiherald.com/news/nation-world/national/artic...
There is information in people's finances that should be 100% private. What if an employer looks at the financials of someone applying for a job and sees they claimed $100k in medical expenses last year because they had cancer? Companies will do that if they have the ability, and people will lose jobs because of it.
It doesn't matter if you make it illegal. I worked a recruiting agency for a while, and illegal hiring practices are incredibly common.