Point (c) regarding interest rates is quite tricky & subtle. At least, you should probably take into account something like the real interest rate instead of the nominal rate, because ceteris paribus it’s much more plausible that only real (ie inflation adjusted) growth of your donation pool matters. I would go even further and claim that, in expectation, you need to outperform the real risk free rate in order to generate a net benefit by donating later. This means that unless you’re happy to take some investment risk and aim to ouperform in real terms point (c) doesn’t matter much. However, imo if you’re at an early point in your career, investing in your future career flexibility by having savings can have extremely high returns, which can outweigh all the other points.
Point (c) regarding interest rates is quite tricky & subtle. At least, you should probably take into account something like the real interest rate instead of the nominal rate, because ceteris paribus it’s much more plausible that only real (ie inflation adjusted) growth of your donation pool matters.
I would go even further and claim that, in expectation, you need to outperform the real risk free rate in order to generate a net benefit by donating later.
This means that unless you’re happy to take some investment risk and aim to ouperform in real terms point (c) doesn’t matter much.
However, imo if you’re at an early point in your career, investing in your future career flexibility by having savings can have extremely high returns, which can outweigh all the other points.