Nuptial gifts in insect (and arachnid) species are sexually selectable visual traits - like eye color, wing size, body mass, wing color, wing flapping, etc. More of this trait (than less of it) conveys signals of male quality to females. The males of many insect (and arachnid) species exploit the visual receptors of the females by displaying an item such as: a dead bug, a salivary secretion, a spermatophore, a leaf, etc., The gift is offered by males to induce high-quality females into mating. The gifts, also, provide valuable mating-incentives to females, as nutritional resources are scarce - severely lacking in many habitats.
I cite reams of evidence from experiments. You distort bio-terms into counter-real clap-trap, falsely attribute the distortions to me then you attack your own bio-term distortions - as though you were attacking evo-bio.
You might have selected a dictionary meaning - which actually aligns with evolutionary biology.
Male nuptial gifts: phenotypic consequences and evolutionary implications - by Carol L Boggs
"Much of the work on insect nuptial gifts has been done to explore the effects of relative reproductive investment by each sex on sex roles and the operation of sexual selection. This work was stimulated by a series of authors, beginning with Darwin."
"Male nuptial gifts are widespread across insect orders, including those with a range of feeding habitats and in a diversity of environments."
"Nuptial gift giving is an excellent vehicle to test sexual selection theory. Male nuptial gifts have primarily served as a case example to study theories of sexual selection."
"We have initial information on absorption rates of internal spermatophores and on the usage rates in oogenesis of materials from both internal and external donations. Most of these data come from radiolabel experiments. Males are labeled with radioactive amino acids and mated with females; then eggs and/or females are tested for radioactivity at intervals after mating."
If nuptial gifts are not literal features of reality, then how did biologists physically isolate them from males, "radiolabel" their production then experimentally test their reproductive effects on females and eggs? A necessary pre-condition for an item to emit streams of detectable radioactive particles is that the item (the gift) literally exist in nature!
Perform this word-stunt now: point to the ceiling and bellow: "This ceiling does not literally exist!". You have committed a referential contradiction. Next, look at what a biologist is holding between a pair of forceps. Point to this object which has been taken from a male of a gift-giving species and scream: "That nuptial gift does not literally exist!". Now, point to a gift-giving insect and assert: "That organism of a gift-giving species does not literally exist!". My regrets to you, you - too - may be a Khuno. (According to him, the latter 2 existents are non-cognitive chunks of literal nothingness - because they are described by the anathemized, sexual selection terms: nuptial gifts and gift giving.)
"The antiquity of spermatophores within Insecta means that the potential for male nutrient donations via the spermatophore or similar accessory gland secretions is probably at least as old as the class."
If these gifts were figments of someone's imagination, then how did they originate in the freakin' Triassic era, functioning in the mating systems of a bewildering variety of insect (and arachnid) species for about ~500M years?
If sexual selection (non-random, reproductive outcomes, driven by preferences for ornaments) did not literally operate in the mating-systems of the non-human, archaic lineage which gave rise to Homo Sapiens, then - according to evolutionary biology, Khuno would not be around to formulate his howler that (to anyone) insects are "VOLUNTARILY bestowing something without the EXPECTATION of COMPENSATION during mating season".