Goodwill's administration cost is surprisingly expensive, and the bulk of your donation goes towards operating expenses like top executive salaries and operations. Heck, sometimes a big chunk of what you give doesn't go directly to people in need.
Despite Goodwill's claim to serve local areas, many of its donations are shipped out of state, or even abroad. This reduces your donations' real reach in your community. You might want to consider giving to smaller, local charities that make the donations stay local if you are trying to help the people around you.
While Goodwill has long touted their ability to provide jobs for people with disabilities, workers have repeatedly complained about pay, benefits, and working conditions. Goodwill may be doing a good thing, but we need to look deeper at the employee treatment.
The worst thing for thrifters is the way that Goodwill sells donated stuff at an increase in price. The donations are meant to be charity, so a lot of people find the expensive prices unrelated to the mission of making goods affordable for people.
Goodwill is trying to be more sustainable and less wasteful, but most donations don't get recycled; they end up in landfills. Things that don't sell at the store may be thrown out, and we end up creating more unneeded waste
Goodwill has also been accused of being opaque about how donations are spent. People don't know what's being raised with their donations or how much of their donation goes directly to those in need.
Goodwill donation centers get slammed with loads of things. This may make sorting and distributing donations more cumbersome, and your goods may not get delivered as efficiently or with care. Smaller, more specialized organizations can probably take care of and distribute the donations more efficiently and faster