I'll start off my response to this with a caveat; the skill assets "might" be okay for solo play.
In multiplayer, they are trash. 3-4 players, the 2nd and 3rd scenarios especially there is simply no time for frivolous use of resources that might "eventually" be efficient or pay itself off. Enemies and treacheries are humming out of the encounter deck, the doom clock is ticking and every action an investigator takes has to have an impact. Someone up above said "the 10th time you use it it won't feel inefficient" or something to that effect; this will literally never happen, ever.
For this reason the cantrip skill cards are absolutely some of the best things you can include in your deck, especially if you aren't taking the LOTR approach that has become common and tailoring your deck to a scenario. You may not want to fight, but even daisy can use an overpower to take out a rat or a cultist that is bothering her and draw a card to boot. You may have no Will checks in deck but being able to buff yourself or an investigator next to you during a bad treachery and draw a card for zero actions/resources is amazing. The list goes on but you get the point; in a multiplayer campaign, every skill cantrip is valuable because every investigator has a primary function, and you will want to group up for the hard parts.
At this point I will give an obligatory "Skids with Hot Streak can do whatever he wants" and asset skills might be good for him. Even then, you are blind spending resources that might just get blown out with the auto fail token, so enjoy that gamble.
TLDR - Cantrip skills are some of the best cards in the game. Include as many as you can shove in your deck while keeping the ability to handle enemies, clues and whatever your primary function is. Don't waste time on skill assets.