Thats a truck bed spray liner. Thats going to ruin the treads. As far as making the treads less "slipery" keep them dry. Or there are peel and stick mats you can place on each tread. Also could go the traditional carpet runner.

Is there a reason you want a high gloss finish?
Although its your choice. A gloss finish on stair treads will look nice for about a month. Then you will start to notice wear on the finish. And yhe smallest amount of wear on gloss sticks out like a sore thumb.

Of course if you go with a runner or mats on the treads then the gloss would be ok without a worry of early wear.

"a product to make wood/laminate stairs less slippery?"

It's called carpet.

And ditto on the high gloss. It is a super high maintenance look that isn't suitable to most people with real lives. And, it can be kinda 1970's bar top cheesy if done poorly.

Yes-carpet. Ive heard of that. Ive also heard of sarcasm.

Im not worried about "bar top cheesy"-the flooring is not.

Its not bowling alley glossy its just not as dull as my satin wood now.

Any other recommendations would be appreciated.

We did wood laminate floors and were advised to do hardwoods on the stairs because the wood laminates don't last as well on the smaller surface of a step. The wood laminate is a floating floor system and the small size of a step doesn't have much room to float/give....I don't work in the industry; this is just was what I was told when I put my kitchen floor in last summer.

The guy who put in the wood laminate didn't really want to deal with building out the hardwood steps and the cost elsewhere made me reconsider....we are now doing carpet on those steps because the other room is carpet and really, really needs replaced.

Laminate is unsuited to stair usage. Choose hardwood or carpet (or both) for them.

A high gloss floor is also a lot of work. You either have to be OCD with a swiffer in your hand and a Roomba running or else you you have to be able to ignore the footprints, spots, dust, and loss of gloss from normal wear. I would suggest runners for traffic paths and on your stairs if you choose to go high gloss, both from the slip and slide perspective and to minimize the wear and tear.

I saw this in the building a home forum

Bona Traffic Anti-Slip. The person that used it said the wood looked normal, but said it was not slippery.

I don't think you will have the gloss though. The poster said that it made an attractive matte finish. Try googling it and see what the images show. If it is too dull you may have to try something else.

Hope this helps!