The PageSpeed Insights is a decent tool who gives a performance report of any website.
The report for wikimedia.it in September 2020 was:
Mobile: 13/100
Desktop: 36/100
There is a lot of room for improvement on this.
Update: November 2020 (no known intervention):
Mobile: 13/100
Desktop: 40/100
Update: April 2021 (intervention by our provider):
Mobile: 36/100
Desktop: 59/100
Update: June 2021:
Mobile: 44/100
Desktop: 73/100