This years Tour was hyped up as super hard because of the number of mountain stages (9 if you are generous) but none of those mountain stages were actually that hard. Stage 2 had the hard climbs far from the finish, stage 4 had a mtf but a really easy one, stage 5 only had one hard climb, the pyrenees stage were both really short (and the 2nd one probably wouldn't even be called mountain stage if it was a giro stage) and the stage to Puy Mary was also more of a medium mountain stage. The last 3 were really tough, but 3 really tough mountain stages doesn't sound as frightening as 9 mountain stages.
Yet because 5 "mountain stages" in the first week alone were so extraordinary for the Tour people jumped on the bandwagon and went on about how hard this Tour was. But remove stage 2, 4 and 6, as all of them were soft pedalled as if they were flat or at best hilly anyway, and look at what remains. 2 pyrenees stages, 2 massif central stages, 2 Alps stages. Standard stuff.
The giro is simply looked upon very differently as the standard for what even is a mountain stage is completely different there. Like, there are 1st category climbs in the Tour that would be 3rd category in the Giro.
Then there is the point that Giro mountain stages are often much tougher than Tour mountain stages.
Then there is the point that the Giro usually has many more medium mountain stages and hilly finales.
Then there is the point that Giro stages are usually much longer.
Really, I don't think it's even a close comparison. That doesn't mean the Giro in general is much harder than the Tour as the Tour field is usually much stronger and the peloton a lot more nervous, but when it comes to the route the Giro, at least this year, is by far harder.