That may have been DOS, but I don't see it here. Quite the contrary, the (hand-placed) unique items/loot seems reasonably rare. That is, compared to other modern games, obviously BG1 is an entirelly different beast of its own (one I miss very much).
Subjective opinion. Let's raise some specifics to make this more tangible, but let me start by saying hand-placed loot does not mean it's not excessive loot in the game. This is a common criticism on this board as well as DOS2, so it is a repeating pattern for a reason.
I take too many issues with what I perceive as a loot/gear focus to address in detail here, but let me quickly summarize the gist of it:
1. There is no real/realistic limitation to the amount of loot the party can carry. Combine this with an excess of loot, hand-placed or not, means the player is incentivised into compulsive "pack-muleing" lest you don't raise enough money to be extorted by the next trader. This permissiveness is not realistic and detracts from immersion. 2. The alternative is robbing every trader blind. The traders tend to have the best gear/money, and as per DOS2 pickpocketing is the most powerful "skill" in the game by far. This completely destroys any risk vs. reward mechanisms otherwise found in the game. 3. Almost all the magical items are "hand-placed" Larian homebrew and quite overpowered, especially for such a low-level setting. They cause all kinds of class imbalances and helps trivialize the content (as do the super permissive, anti-immersive rest mechanic as do the easy advantage as do the elemental effects). Ie. the 18 int headband which allows for metagaming character builds dumping int, the magic missile amulet doubling the damage, the staff providing +5 average spell attack rolls and 1-4 dex saves. The love-child of your namesake at Larian, is the Wizard - and it shows! 4. Despite arguably overpowered magical items being readily available, decent non-magical medium or heavy armor don't even exist in the game (outside Lae'Zel). Maybe to offset the D&D RNG problem - high AC makes for more misses and can potentially unbalance a low-level setting. Still this breaks the internal realism of Forgotten Realms and is detrimental for my immersion. 5. Gear becomes so important that it detracts focus from character and character build. Some of the gear is already arguably character defining. And this is available from level 2 onwards.