>Suffering is on a scale. Its better that a few innocent people sit around for a few days than one guilty person getting out and killing someone.
Firstly, pretrial detention averages 50-200 days, with some sitting in jail for years without trial. Secondly, the vast majority of those in pretrial detention are there for non-violent crimes. Thirdly, about 60% of the population of jails in the US are in pretrial detention.[0]
Remember, these are people who have not been convicted of any crime.
Calculate how long could you keep your job, your house and/or custody of your children if you were sitting in jail? Two months? Six? A year?
After you do that, consider that a large segment of Americans would have a hard time scraping up $400 for any sort of emergency -- especially if they can't work because they're in jail.
If there is a genuine flight risk (much more likely for those who can afford bail) or evidence that the accused may be a danger to the community, they should be held until trial without the opportunity to be released. But only if there is actual evidence that this is so.
Otherwise, you're essentially criminalizing poverty.
[0] https://www.pretrial.org/get-involved/learn-more/why-we-need...
Edit: Reorganized for clarity.