I can't see any blurriness here either, but there is a lack of definition on certain materials and/or wrong curvature of what seems to be fresnel falloff. Somethings you can try:
- Check smoothing groups on objects.
- Lower any amounts of Coronaroundedges applied in bump.
- In case of using normal maps, make sure the correct gamma is applied.
- As mentioned previously, double-check your image filter settings.
- If displacement is being used, do consider lowering its screen or world size.
- Lower the noise limit threshold of your scene to 2-3% and do apply a high-quality denoiser at a preferred amount.
- Corona VFB comes with the Sharpening/Blurring rollout tab, you can find useful utilities in there.
Lastly do note most renders are not being posted "raw" in galleries/portfolios, post-production software like Adobelightroom and AE come with tools that can enhance, denoise, clarify, sharpen, dehaze, etc. renders to another level.
Do keep us posted, and please let us know how we can assist you further.