Hmm. I worry that, without significant modeling and measurement of relevant variables, the causality is suspect. Neither bee nor bird response is the same dimension as what we usually mean by "smart", and they're very likely optimized for different cost-benefit values (specifically, protection of central hive vs distributed nests or individual birds, and cost-of-replacement of individuals lost in the action).
The leap to humans, with type-2 reasoning in addition to automatic behaviors, is pretty huge.
I think the rule is not necessarily "smarter units make a worse collective", but rather "it is more difficult to make a collective out of smarter units (but when it succeeds, it can be even better)". Humanity is unparalleled at eliminating larger predators.
Bees sacrifice their lives for their biological closest relatives. Birds have small families, so the cost of sacrificing their life is an important factor. Humans also have small families, but they can use prestige and money to incentivize heroic behavior.
So my proposed analogy would be that smarter populations can win, but they cannot achieve it by merely copying the behavior of stupider populations. They need a new solution that leverages their strengths.
Nitpicking at the example, worker bees do not have offspring; the best way for them to spread their genes is to protect the queen and thus, the hive.
Birds can have offspring, so self-preservation instead of risky attacks is optimal for individuals of a flock (of genetically unrelated individuals).
It's not that the group is less intelligent, rather that the individuals of the group have different goals (self-preservation vs hive preservation, though the end goal of maximizing fitness is the same).
But genetic fitness breaks down as a metric when you add culture to the system, so application to humans is limited.
The Hierarchy
There is a hierarchy in life from simple cells to complex cells to multi-cellular creatures to creatures that often live in a groups like birds and bees. As we go up the hierarchy the lower levels have less individual say. For example the mitochondria have no individual life or fitness outside of the cell, and the cells success is not meaningfully measured outside that of the organism in multi-cellular creatures.
Generally as we go up the hierarchy the higher level is more complex and smarter than the lower level. A brain can think, a neuron cannot. A hive of bees or ants is more capable than an individual.
Bird patterns
However you see sometimes see relatively smart creatures such as birds making simple patterns. We are told that this is beautiful, mysterious and presumably smart in some way. However a simple geometric or predictable pattern does not allow intelligence or sophistication. A perfect sinewave contains almost no information and no intelligence.
See here and here.
Is this really the best defense against a larger predator by the birds?
Bee defense
Here is what happens when bees use their best defense against an individually superior attacker. You wonder if the smaller birds could simply swarm the larger attacking bird, as they have vastly superior numbers.
In this case it looks like the flock of birds is less smart than the hive of bees, in spite of an individual bird being a lot smarter than an individual bee. Sometimes it can appear to go even further than that, say a crowd of people panicking is arguably worse than the least capable person in the entire group.
A different rule?
The more complex the pieces the less well they fit together unless there is strong pressure otherwise. Less intelligent units can form a better collective. This is especially true in terms of the relative capabilities. The difference between a single ant and an ant colony is greater than that of an individual wolf compared to a pack of wolves. This is even more extreme when comparing multi-celled creatures to single celled ones. The advantage of the collective is less the larger, more complex the pieces are or greater as the pieces get smaller, such as for cells.
However what about humans? We form very effective collectives, even sacrificing ourselves for the group in spite of our intelligent individuality. Language, consciousness, communication and the imagination to communicate a shared vision enable us to make our complexities all work to create a greater whole. We are an exception to the diminishing collective returns with increasing size/complexity rule.
How about tech?
I first though about this many years ago, and it led me to believe that RISC and GPU based architectures would win out over CISC/Intel. We have seen that play out again with AI design. The simple transformer design overtook the more complex competing AI systems when vast computation power was available. Its not clear if this applies to AGI. Smaller models may be able to outcompete larger ones when organized properly, or larger ones could be able to communicate effectively to overcome these potential problems in a way analogous to humans.
You can also of course draw analogies with large organizations and more agile startups, the small businesses of capitalism vs centralized control.