To you maybe not. It bothers some people and especially in cases when the stream isn't optimal and the scene is dark it can be pretty bad.

Another difference is multichannel audio. It's much less compressed on 4k Bluray, so if you have a surround setup most people report easily being able to tell a difference.

Also older movies with film grain is something streaming struggles with. (Check out this video about how confetti wrecks YouTube quality for an idea why) 4KBD has a much higher bitrate and will handle this noticably better. A proper scan of old film movies can still yield nearly 8k resolution footage! This also applies to any scene even in modern movies with a ton of stuff moving at once especially if the camera is moving around. The bigger and/or closer your screen is the more noticable this is.

If you care enough to have a decent home media setup, surround sound with a large 4K HDR screen it's worth it.

But yeah for most people streaming is perfectly fine on the quality front.

But also you have the other benefit - you own the damn thing. It can't be taken away. They sometimes have extra content with the discs. It doesn't cost you a monthly fee.

I stream many things. But if I really like something I'll grab the Bluray.