"As a French" ne veut rien dire en anglais. Il faut rajouter man, person ou quelquechose. Frenchman, French person, French citizen.
The demonym for France is "French," so it's not wrong (even if it doesn't sound right.)
Nor "Frenchie" while we're on the topic. It sounds really weird. It's also commonly used to refer to a french bulldog !
Pedantry attracts dislike. One may be right to state something, yet wrong to call it out in public.