Can I use tile or hardwood to cover a Formica bathroom counter top?

either --- if you use wood, you will need to seal it with a good epoxy -- I'd suggest a Marine Grade --- I like wood ANYTHING better than tiles .. so much 'warmer' -- and not as apt to break something should you drop a glass container on it! Wood would be easier to work with, lighter weight, no moldy grout LOL!

Tile counters are very dated and usually the first thing people want to demo. You can buy counter refinishing kits if you can't afford new counters (which can be really pricey for a double sink).

There is a website In My Own Style where Diane has refinished her countertops. They look fabulous. Giani and Rustoleum also make a countertop refinishing product.

Here is one more idea: https://www.hometalk.com/diy/kitchen-dining/kitchen-dining-furniture/changing-up-an-orange-formica-countertop-with-concrete-18147786

Changing up an Orange Formica Countertop With Concrete