Those losses can be made much less than that. Theoretical minimal losses are on the order of 1-2kWh per kg, and in practice not much more than that[1]. Further efficiency improvements can get reality even closer to theoretical.

Most of these arguments are increasingly outdated, as I mentioned before. We're at the point where hundreds of billions of dollars are being spent on hydrogen right now[2]. So naysayers are more accurately described as being out of touch with latest events and not people with any special knowledge.

[1] https://www.hydrogen.energy.gov/pdfs/9013_energy_requirement...

[2] https://www.jwnenergy.com/article/2020/7/8/europe-unveils-pl...