Parmandur
Book-Friend, he/him
The fact that the ability modifier can be so much greater than the proficiency bonus, especially at low levels, was one of the first things that seemed really off with this edition. I mean, if someone goes out of their way to become proficient in an obscure skill, then they should definitely be the go-to person for using that skill when it comes up, regardless of natural talent. If the paladin with proficiency in Religion is less-knowledgeable about it than the wizard who isn't, then what was the point in even writing down that proficiency?
In my game, I increased the magnitude of the proficiency bonus by +4 across the board. If you're trained in something, then you're at +6 next to anyone who isn't, and that goes up to +10 by high levels. Expertise just lets you substitute your proficiency bonus in place of your stat modifier, whenever that's better. (Stat bonuses are also increased by +5 across the board, so they go from +4 to +10 instead of going from -1 to +5.)
The RAI for Proficiency is that many skill attempts are best gated by Proficiency (see every published Adventure for 5E).
The Paladin might only have +3 for Intelligence, but the Gnome Wizard with 20 Intelligence lacking Proficiency in Religion cannot even roll to identify the holy symbol in the tomb.