i mean, it's a british series set in britian by a british author with british characters speaking british english. why would they be saying 'parking lot' instead of 'car park'? that doesn't make sense!
and even at 8 i don't think i was so stupid that i couldn't figure out what an ice lolly was from context clues. furthermore, context clues are important for children to learn, not to mention dialects in general.
plus it seemed very inconsistent? some of the obvious slang they'd change but they'd leave in stuff like 'trainers' or 'snogging' in the US versions which confused me even more as a child because i was used to being spoon-fed the US vocab -- which doesn't immerse you in the setting as much and get you used to hearing the slightly different words as often.
Some say Fry is not so good with his rendition of female characters' voices.