I saw something in another thread (quite a while back) that mentioned using something to bring out the grain in the wood after it had been sanded. Then you can paint, sand, paint, sand, etc. The sanding helps bring the paint to an even level, effectively filling in the grain. I have a third bathroom that I'll update some day. (Not any time soon.) One of my plans was to just sand and paint it repeatedly to get a nice smooth surface. Then I can replace the top parts (sink, counter, faucet), tear out the lame wallpaper, etc. From 1982 to 200x! Presto!

Stain only works on bare wood. Applying stain to a finished surface fails because the stain cannot penetrate. Oak and ash have variegated grain characteristics, most other woods do not have. stains/finish remain in the deeper grain pattern after sanding and some attempts at brushing. Stain cannot penetrate and the application of stain then results in blotching. Staining to a lighter color does not work, since stain is done by adding color. You could have the doors/drawer fronts professionally stripped, but the cabinet boxes cannot be removed and sent out for stripping.(Actually, that can be done, but replacing the cabinets would be better). Painting oak(a personal opinion) simply winds up looking like painted oak, since the grain patterns show. And that looks(to me) horrible.

Duplicate. Repeating the same post still without pictures isn’t how this is done. Add pictures to your first post, here. Pictures are required. https://www.gardenweb.com/discussions/5897514/update-my-kitchen-without-painting-oak-cabinets#n=3

I kind of like the wood, it’s not a bad stain-and not the dreaded honey oak! You didn’t mention a budget so I’m assuming there isn’t much of one. The biggest offender is the wallpaper. For an almost-no-budget change, remove the paper and paint a warm white. Change hardware to black. Bring in accessories that are black and white. You have a great start with the rug. Black and white with dark wood is a great look. Good luck!