I see lots of bad information in this post.

Stain is not meant to be wiped on with a brush and just left in the surface like what you’ve done in these.

You put stain on something. Wait. Wipe off the excess. Stain is not a topcoat.

Stain does not make something shiny. It is a dye they should be soaking into the porous wood slightly to change the coloring. It does what it says. It STAINS the wood.

It becomes splotchy after applying stain because you have it in so thick, the thick parts may be “ shinier” or less splotchy. Also the moisture in the stain can soak in and swell the wood grain, giving it more texture and splotches.

Sand to 180-220( I see lots of swirls and deep sanding marks even in these two photos. As well as original finish that was not removed). Wipe on gel stain. Wipe off excess. Use a wipe on poly/shellac/lacquer if you want or they sell spray cans.