In 1895, at the birth of film, every effect was practical. The Lumière brothers, Georges Méliès — everything you saw was built, directed and shot. Digital post-production did not exist.
VFX are a powerful instrument, but they have a fundamental limitation: human perception recognises the difference between what is real and what is computed. A CGI explosion looks different from a real one. A digitally-enhanced space feels different from a real location.
Practical effects — effects created on set, in reality — bypass this problem entirely. They are real, and they look real, because they are.