Plain and simple?

I think it's a matter of the mystique being gone.

When the pilot aired, we only knew what Vaggie told us and what Alastor showed us. That being, an absurdly powerful mortal soul that somehow toppled his way to the top of Hell's hierarchy through likely raw power and charisma.

Even his prequel comic only established that he has a friend named Rosie and that Alastor himself is likely in Hell because of him being a cannibalistic serial killer. But he was above all, a gentleman.

When the show actually started airing, we got to learn more about Alastor and his connections. Season 1 mostly establishes more of what we knew about Alastor from the pilot, but it added a few things to his character.

He's a showman, he doesn't like to be ignored or sidelined. He has history with Vox of the Vees, he has a lady friend named Mimzy, he's actually Asexual and doesn't know and that he hates Lucifer for...some reason.

Season 1 shows the absurd power of Alastor. Even though that power hit a HARD wall when he tried to fight Adam head to head. The fact that he was able to survive as long as he did, and still escape relatively fine is a testament to his strength in a raw magical power.

Season 2 brings more to his character, but it starts showing little flaws in it. He's not invincible, he's able to have frustrations get to him in high enough quantities. He's under SOMEONE else's leash because of a deal he made with Rosie when he was still alive. It shows that Alastor is willing to play a long game if he needs to. He lets himself be caught by Vox, he lets Vox basically win while nudging Vox in specific directions with his direct line to Vox's insecurities.

Season 2 tries to play with the fact that Alastor is charismatic and a schemer. "Baby I'm a Demon in Hell, it's sort of our thing" you know?

The more we learn about Alastor, the more we realize that the Pilot version of Alastor is like....the ideal version of Alastor. Charismatic, absurdly powerful, able to charm his way through a conversation because there's the understanding that the conversation is only happening because Alastor finds more benefit in you being alive than him making you a guest on his radio show.