What if Italy never joined the second world war?

So in our timeline, Italy joined the Axis on June 10th, 1940 to capitalize on the initial German victories and hoping to gain some land on it own in Southeast Europe and Africa. However, this invasions failed miserably and Germany had to bail them out each time, costing them troops for the fight against the USSR and in invading the British. Italy itself would be invaded in 1943 and even more Germany troops had to be stationed to prevent total collapse after Mussolini was overthrown and an invasion of Germany from the south.

So how would things go had Italy taken the route of Spain and remain neutral, perhaps giving some support and volunteers to Germany, without a formal declaration of war? I think it would actually help the Axis.

1. North Africa is more stable, with only French Africa being a possible target, which would be much harder to take over due to its sheer size.

2. Germany has much more resources troops and generals (Rommel aka the Desert Fox would now be focuses on the Eastern Front and we know how much of an expert he was in our timeline) which could have tipped the balance during Leningrad and Stalingrad and lead to a Nazi Victory, although uprisings would also be occurring, but the additional troops could take care of that.

3. Without an easy invasion point in Europe like Italy, it will now be much harder for the Allies to plan an invasion, and German defense would be much stronger in France and the Low Countries, and help defend the skies against bombing campaigns, which were detrimental to Germany in our timeline.

I think with these 3 points, it is possible for the Axis to actually win the world war, although tensions would arise between Italy and Germany as the former didn't gain any territory and are resentful of Germany's power.

Anyways, that's just my scenario. What do you guys think?