There is a reason Gloves of Dexterity don't exist in 5e. They're way too powerful, with the way that 5e's design has made Dex into an uber-stat - governing to-hit & damage of both ranged & finesse melee weapons, AC, initiative, one of the Big 3 Saves, and plenty of skill checks.
Gloves of Dexterity that add +2 to Dex or that set your Dex to 14 or maybe 16 would be ~okay, but setting Dex to 18 is much more powerful than ~any other stat boosting item.
You can't really compared BG1&2 with their AD&D 2e rules to BG3 using (the framework of) 5e rules.
