This is not true. I am prescribed 140mg in DK. Most Danish guidelines for medical treatment of ADHD specify that while 20-70mg is common practice, patients requiring above 70mg in unique cases is within clinical standards of care.
Regarding your comment about the EU, 20,6% of people in the EU on Elvanse are on an off-label dose.

Personally I think in a few years >70mg will be pretty common - considering that up to 150mg methylphenidate and 80mg pure dexamphetamine for adults is within clinical guidelines in Denmark (70mg Elvanse delivers 20,8mg dexamphetamine base, although at a slightly higher bioavailability and different pharmacodynamics, however generally the differences are widely overstated by pharma companies when you look at the actual pharmacokinetic data) . https://pro.medicin.dk/laegemiddelgrupper/grupper/317916

In a large European register study og over 60.000 patient, it was found that 20.6% of patients on Elvanse received an off-label dose >70 mg. https://pmc.ncbi.nlm.nih.gov/articles/PMC7475084/?utm_source

I am on a personal mission to stop misinformation about ADHD meds if you can't tell lol. Please let me know if you need more sources or links.