Discussing the educational pros and cons of charter schools in isolation is one thing.  We’ve done that in this space before, in what I hope was a balanced discussion. Looking at the past performances of charters in terms of stewardship of taxpayer money, however, is another scenario entirely.
Consider these excerpts from assorted articles and/or national educational blogs.  (Footnotes represent different sources, gladly shared upon request).

*Charters are not public common schools. They are publicly-funded, privately-managed private schools subject to market forces. Charters have no community or geographic base. They have no legal obligation to serve any designated population of students and no legal obligation to stay open.¹

*Charter closings are routine throughout the nation. In Ohio, 291 of the 600 charters authorized either didn’t open (after taking public money) or closed for various reasons.¹

*Feds awarded $20,272,078 between 2006 and 2014 to Michigan charters that closed or never opened; then in 2018 the state of Michigan was awarded $47,222,222 to expand charters.⁵  (Note:  Michigan is Betsy DeVos’ home state.)

*Despite the report from the Network for Public Education showing that 1/3 of the grants by the federal Charter Schools Program are awarded to schools that never open or that close soon after opening, the money keeps flowing.²  (Note: Article has examples.)

*Betsy DeVos has awarded a huge grant of $116,755,848 to the IDEA charter chain to open 20 new schools in El Paso. IDEA opened its first El Paso charter last fall. IDEA has received a grand total of $225 million from the federal Charter Schools Program. This rapid charter expansion is likely to swamp the underfunded El Paso public schools, if not eliminate them.³

*Across the nation, educators have awakened to the reality that charter schools are a threat to the health and even survival of public schools. For that reason, charters have become a major point of contention in teacher strikes, from Oakland to Los Angeles, and even in West Virginia.⁴

I do not think it is biased or unreasonable to draw some conclusions from these and other sources:

1. Completely apart from the question of their educational value, (for which the results appear to be mixed), charter schools too-often continue to have a questionable or poor track record, in terms of stewardship of public (taxpayer-funded) money.
2. Partly, it seems, this is because of the lack of financial (not to mention educational) accountability. (Note: DeVos family money helped defeat a proposed accountability bill in the Michigan legislature before her tenure as Secretary.) As a result, of course, this lack of accountability leads to evidence of greed and/or fraud.
3. The incredible sums of money being awarded to these entities are certainly not helping public schools. Indeed, for a variety of reasons, they may be fatally harming some of them.
4. In spite of this, the Department of Education, at the hands of Betsy DeVos, continues to pour huge sums of money into charter schools, seemingly ignoring the mounting evidence that this may not be the wisest idea, and without bothering to step back and survey the landscape.

This is a disastrous, if not criminal, scenario.  The (rhetorical?) question, of course, is WHY is this happening?  Is there an agenda?
Allow me to close with the same paragraph used in the last column:
As a nation, we’ve put up with similar nonsense from this Secretary for over two years now.  How do we make the ongoing pleas for sanity and reason any louder?  What options do citizens have for receiving more accountability from her?  What can we do in the meantime?  The future of our schools may depend on finding some answers.