Why yes Stealth gets much, much better, if you really focus on it.
Rogue level 10+ gets the special ability to always get at least 10 on skill rolls.
From that point on, assuming you pumped into Stealth / Dex everthing you got, and your gear is right, well, you can pretty much stay out of sight all day.
Before that point picking Halfling as race helps; they reroll critical failures AND they get advantage on stealth; but the later is true only for the Lightfoot Halfling subrace. Though you can give anyone advantage on all Dexterity based skills by casting Enhance Ability: Dexterity aka Cat's Grace on them. Thats a Concentration spell though, so your caster cant cast any other concentration spell. I know of no way to get the "Lucky" racial trait of Halflings through spells though.
