Compact cameras often have higher megapixel counts because they use much smaller sensors with more densely packed pixels, and because megapixels are an easy marketing number to advertise. DSLRs usually have much larger sensors, so even with fewer megapixels, each pixel can be larger and collect more light.

That brings important trade-offs. Very small, densely packed pixels tend to produce more noise, especially in low light, and compact cameras often rely on strong noise reduction that can smear fine detail. Also, the lens on a pocket camera may not have enough resolving power to make full use of a very high pixel count.

DSLRs are typically designed around overall image quality, low-light performance, dynamic range, and sometimes shooting speed rather than just maximizing megapixels. Lower-resolution DSLR models may shoot faster and produce cleaner images at high ISO.

So yes, compact cameras can have denser sensors, but more megapixels does not automatically mean better image quality. In practice, a lower-megapixel DSLR will often outperform a higher-megapixel pocket camera because of its larger sensor, better light gathering, and stronger lens system.