What this discussion tells me is:
If you
like how kobolds can still hit high-level characters, don't hand out many items with pluses.
If you
dislike how kobolds can still hit high-level characters, hand out many items with pluses.
To me, it appears the complainers and detractors have no case. Or more specifically, their complaint is a paper construction that's easily fixed by how you as the DM hands out magic items.
Don't complain bounded accuracy is broken and hand out +3 plate and +3 shields.
Don't complain how high-level heroes can be taken down by village farmers; instead hand out +3 plate and +3 shields.
To me, this discussion proves 5e is well on its way to both having the cake and eating it at the same time... since both kinds of D&D players can have it their way
The only group left out is the ones that like to complain about how broken bounded accuracy is in specific (and highly theoretical) cases which assume players can hand-pick exactly those magic items that push against the game's limits the most...