Three things:
- Is rolling 1d20 annoying in early level 5e - yes, but then again I can't blame Larian for using this mechanic.
- Adding modifiers for missing can be a solution, but I think it is much more fundamental task than tweaking monsters. Plus, might be confusing for players too, whereas rolling 1d20 + prof + skill is fairly straightforward.
- I don't think HP bloat is a thing in BG3, mostly complaints talk about goblins. And as others mentioned the Goblins don't have wildly different HP/AC compared to other monsters at their CR.
