I can't not anymore…
OK, lets try.
First, lets embrace the reality that once Germany started running amok, there was less chance of keeping Mussolini on the sidelines than getting certain current world leaders to stop tweeting.
That being said, let's deconstruct.
If Italy had remained neutral, there would have been no need for the Brits to do their recon in force that resulted in a rout of the Italian army in North Africa.
Without which there would have been no need to supply and reinforce North Africa through the teeth of Maltese resistance,
and no DAK,
which would have avoided any need for an ineffective Axis air effort to suppress Malta,
nor, an ineffective Italian naval effort to deny access to the central med to the Brits. The UBoats contributed far more than the Italian surface fleet. Ark Royal, Barham, and they're just the top of the pile.
Nor any need for the Italian air force to spectacularly fail to menace British naval opns in the Med.
If the Italians had stayed neutral, the med becomes a non-issue, apart from Brits efforts against the (presumably) semi-neutral Vichy French coast, and French North Africa.
A Neutral Italy doesn't strike Greece from Albania. Hence no need to involve Yugoslavia, nor Bulgaria.
No need to attack Crete, to which the Italian navy ultimately committed, what? A handful of escort destroyers.
Southern Europe becomes a bastion of neutrality against which even Churchill cant cobble together an excuse to intervene.
There are no Italian troops to help occupy Yugoslavia, but wait, there's no need to occupy Yugoslavia. There are no troops to help in Russia, but Barbarossa goes off on schedule, sparing Germany the loss of PRICELESS weeks.
Italy does not require German troops to assist in its' defense, nor become an occupying army to guard and protect against an Allied invasion in 1943.
Apart from a brief fling as part of the Battle of Britain, an occupation force in Yugoslavia and Greece, and as Auxilla in Russia, the only places the Italian military made any kind of contribution was in the Med and Balkans, which would have been better for Germany left as neutrals.
An aggressive Italy might seem, on its' face, as a good idea for Germany, but in reality Italy was Germany's well meaning but daft brother in law, who keeps trying to help, but somehow always manages to find a way to make things worse.
Sorry, HURT.