Accidents happen and considering the amount of waste there would be have to be quite a few launches.

I'm not sure if there is a good list out there, but just some examples from memory: just last month space x failed to deliver satellites in the right orbit and I think one of the other incidents at the end relates to this one that actually exploded.

The second one ofc is a bit older, but still what is an acceptable risk to take when handling radioactive material? And the recent one also wouldn't be fun.

I would also imagine that handling the waste on the ground would make everything much more difficult until the launch.

Putting things into space is extremely expensive in both money and harm to the environment.