pics

Earplugs are so tiny that carrying two pairs is negligibley different from one. I have used multiple pairs simply because I've misplaced one during the night (fallen out my ear and rolled off the bed) and I'd rather have a spare than have to turn a light on and search.

As to the eye mask, it depends how much you care about light. I find that many hotels have too much early morning light for me, so I use it more often than not. But even if it was only 10% of hotels, carrying a flat, compressable 200g item would still be worth it. Particularly because you often can't tell until the dawn whether the light will be an issue, so having it available makes more sense than having to pick one up at a 7-11. But if you only use it 1 in 100 trips, or you're OK with disrupted sleep, then it's a different evaluation.

I carry a pair of earplugs because mine block 10dB, much less than most. It’s the most general use sound reduction and is rare, so I find it worth carrying. Before that I didn’t, because:

Most hotels have earplugs and eye masks that they’ll provide for free. So I only bring my own eye mask for long flights. If you’re only concerned about sleep quality in bed, that’s not a bad option