We had the same issue in our old kitchen. If you zoom in on the sink, you can see the wider cover that was added to cover the holes and, on the right (under the soap 😀) is a matching cap for the sprayer hole. I assume you have an undermount sink, but this will give you an idea. There are good options out there. Be sure to save any extra parts to the faucet. When we renovated we were able to reuse the faucet without the base because we had the other mounting hardware.

Personally I hate the large base plates. Do you have 4 holes? You can get a bridge faucet and another sprayer. OR, one of the holes can be. used for a dish soap dispenser, and another for instant hot water.

No base plate. As I look at it again, it’s actually three separate holes: one handle, one faucet, one sprayer.

Get a single lever faucet for the middle which will can come with a matching soap dispenser. Install a matching garbage disposal button; less than $100.00. Three holes filled.

A good granite guy can pull repair material from the back of one of your splashes and fill a hole or two, but that can be pricy. These can't be seen when standing at the sink:

You can replace your sink with one with a faucet deck and all unused holes are eliminated:

If that 15-year-old has been leaking, the nut may be oxidized to the shaft; you'll only get it off with a grinder with a diamond blade. Don't touch the deck when you do, or drop the sink and cut it off from underneath.

Thanks, Joseph. I think the soap dispenser plus disposal button might be the way to go. Don’t think I want to replace the sink with a smaller one to get the faucet deck. (and, yep, the sprayer is leaking and the valve is gone in the faucet, which will cost the same amount to replace as a down payment on a much better one.). It‘d probably be easier from a hole-filling perspective to just repair it, but it wasn’t that great to begin with (inherited when we bought the house two years ago), and, leaking sprayer.