Certainly charities exist that are ineffective, but there is very strong evidence that there exist charities that do enormous amounts of direct, targeted good.

givewell.org is probably the most prominent org recommended by many EAs that does and aggregates research on charitable interventions and shows with strong RCT evidence that a marginal charitable donation can save a life for between $3,000 and $5,500. This estimate has uncertainty, but there's extremely strong evidence that money to good charities like the ones GiveWell recommends massively improves people's lives.

GiveDirectly is another org that's much more straightforward - giving money directly to people in extreme poverty, with very low overheads. The evidence that that improves people's lives is very very strong (https://www.givedirectly.org/gdresearch/).

It absolutely makes sense to be concerned about "is my hypothetical charitable donation actually doing good", which is more or less a premise of the EA movement. But the answer seems to be "emphatically, yes, there are ways to donate money that do an enormous amount of good".

> giving money directly to people in extreme poverty, with very low overheads. The evidence that that improves people's lives is very very strong

When you see the return on money spent this way other forms of aid start looking like gatekeeping and rent-seeking.