Noise-canceling headphones have gotten very good at every price tier in the last two years. The $50 pair from five years ago that barely worked is not the same as the $50 pair today. That said, there's still a real performance gap between tiers, and the decision comes down to what you're canceling out, how long you wear them, and whether Bluetooth multipoint matters. Here's the honest breakdown.
The Sony XM5 has been the standard recommendation in noise-canceling headphones for two years because nothing at its price ($279–350) consistently beats it. The ANC is exceptional — it handles airplane engines, open-plan offices, and street noise better than everything except the Bose QC45. Sound quality is excellent (Sony tuning leans slightly warm/bassy, which most people prefer). 30-hour battery. Multipoint for two devices simultaneously. The one complaint: they don't fold flat, which makes them slightly more awkward for travel.

If you're in calls all day, the Bose QC45 is the pick. Bose's microphone system is better for voice pickup than Sony's — callers hear you more clearly in noisy environments. The ANC is a hair below Sony's for blocking low-frequency sounds but equal on mid-range. They also fold flat, weigh less, and have a more comfortable over-ear fit for all-day wear. At $279, same price as the Sony — it's a genuine tie that comes down to use case.

The Soundcore Q45 is the headphone that surprises people at $60–80. Multi-mode ANC (transport, indoor, outdoor), 50-hour battery (genuinely outstanding), and sound quality that competes with headphones at twice the price. It folds, has a carrying case, and the ear cups swivel enough for different head shapes. If you don't need the absolute best ANC and want to spend under $100, this is it.

At $50, you should not expect the ANC performance of a $280 Sony. But the Edifier W820NB Plus offers functional ANC that genuinely reduces background noise (not eliminates it), 49-hour battery, and sound quality that has no business being this good at the price. For commuters, students, or anyone who needs headphones to work without spending $200, this is the answer.

For regular commuters, frequent fliers, or anyone in a noisy office: yes. The difference between $50 and $250 ANC is significant in real-world use. For occasional use, mid-range ($70–100) covers most needs.
Sony XM5 for general listening and better ANC on low-frequency noise. Bose QC45 for calls, lighter weight, and all-day wear comfort. Both are excellent — choose based on your primary use case.
Some people use them. They're not ideal — most over-ear headphones are uncomfortable lying down. Purpose-built sleep headphones (flat-profile, soft material) are a better choice if that's the primary use.
Yes. Many people use ANC headphones with no audio for focus work and open offices. The ambient sound reduction alone is useful even without playing anything.