I very much agree (and just made a post about the same thing because I didn't see this one until now), the skill checks are displayed in a very strange way. You CAN mouse-over to see the numbers but the way it's documented it pretty much says that you roll D20 + skill modifier against a difficulty that is Target Number - skill modifier. Which is silly and incorrect

I feel like hiding the actual numbers of the skills that are some of your characters core features, and something you aim to improve throughout the game, is rather shooting oneself in the foot, design-wise, as it basically hides away character progression. Sure, you might've raised your proficiency bonus and put on the Magical Hat of Deceptive Swagger but the game will you, all game, only show that you roll a D20 against a number which is nowhere near as cool as being shown that your hard work has paid off and you now get to add X to the dice roll when attempting a skill check.
Also, mechanically reducing the DC of the skill check instead of adding the ability modifier poses a potential problem since 1 is a natural stopgap.
Lastly, I'd just like to quote the D&D 5th edition Player's Handbook, page 174:
"To make an ability check, roll a d20 and add the relevant ability modifier. As with other d20 rolls, apply bonuses and penalties, and compare the total to the DC. If the total equals or exceeds the DC, the ability check is a success - the creature overcomes the challenge at hand..."