So ... I'm wondering why we should put up with an increase in the amount of disk space required for segwit for the same number of transactions?

Why do we NEED segwit?

Simply increasing the block size will have the same effect without making individual transactions bigger.
segwit makes individual transactions bigger.

Now the only argument I've seen given for this is that if you ignore the segwit data you can run a smaller blockchain.

However, if instead you run a pruned blockchain it will be smaller, so I see the segwit excuse as FUD.

More so, saying you don't need the segwit data is the equivalent of saying SPV mining is OK.

As for malleability, so anyone wanna say why that can't be done properly on it's own without segwit?

Anyone got some answers that doesn't skip over and ignore these issues?