Modern haiku is not hokku. It is generally not even haiku.
We have seen that a hokku is a written thing-event in which an unspoken significance is perceived. It involves Nature and the place of humans as a part of Nature, and it is set in the context of a season.
Shirauo ya sanagara ugoku mizu no iro
Whitebait ya just-like moves water ‘s color
The whitebait —
Just as though the color of water
Raizan got it exactly right; the translucent whitebait fish does look like the water itself has taken on a definite form and is swimming about.
If we compare that hokku with a “haiku” by Shiki, we see something interesting:
Nure-ashi de suzume no ariku rōka kana
Wet-feet with sparrow ‘s hopping verandah kana
With wet feet,
The sparrow hops
Along the porch.
What distinguishes the two verses? Both are set in the spring. Both involve a thing-event. Yet one is a hokku, the other is called a “haiku.”
Both are really hokku in their aesthetics, but by Shiki calling his verse a “haiku” he automatically excluded it from the possibility of its being used –ever — as the first verse in a series of linked verses. In this case, that is really the only difference.
We can see from this that for the most part, Shiki just continued to write hokku, but insisted on calling his hokku “haiku” because he did not care for the practice of linking verses and wanted to discourage that practice.
One can deduce correctly from this that in general, the “haiku” of Shiki were really just hokku under a different name. Some are better, some worse, and there is a tendency in many to shallowness and mere illustration. Nonetheless, if Shiki had not insisted on calling his verses “haiku,” generally no one would bat an eye if they were included in hokku anthologies.
One may also conclude from this that “haiku” has changed drastically from what it was in the work of Shiki. Modern haiku often bears not the slightest resemblance to either hokku or to what Shiki practiced as haiku. Instead, as I often repeat, it is a new verse form created in the West, primarily in the latter half of the 20th century, from misunderstandings and misperceptions of the hokku combined with Western notions of poetry and the whims of “recent” Western writers.