Why can't classic Sonic speak?

Miraculously, 'Sonic the Hedgehog' is a fine movie

Mom on X: I can't imagine him talking without his huge singular tooth giving him an slurred full mouth voice. / X

Shadow won't be brought to the Sonic Classic series

Classic sonic - Buy Royalty Free 3D model by Gabrielgt16 (@Gabrielgt16) [b3507ac]

Modern sonic meets his classic self and tries to get him to talk (2011, colorized) : r/SonicTheHedgehog

Sonic Superstars Sees The Return Of Classic-Style Sonic With New Visuals

Sonic The Hedgehog - By the Mania, For the Mania. Happy 4th Anniversary, Sonic Mania! 🖌: Tyson Hesse

How come Younger Sonic can't talk? : r/SonicTheHedgehog

Sonic Forces SHOULD CLASSIC SONIC SPEAK? Discussion with Trailer and Modern Sonic Gameplay - (1080P)

Super Sonic: creating the new sound of Sega's hedgehog hit, Sonic the Hedgehog

Where does this idea that Classic Sonic has to be cutesy/mute come from ?

How come Younger Sonic can't talk? : r/SonicTheHedgehog

The fact that Classic Sonic is older than Modern Sonic, isn't a problem anymore, since they're considered different people now : r/SonicTheHedgehog

Review: Sonic Generations – Destructoid

Sonic The Hedgehog 1997 Treasures Inc. Talking Plush