The "density" of the shield is called shield coverage. Copper is expensive, and in a coaxial transmission line, the shield is most of the copper. So if you want to reduce cost, reducing shield coverage is a good way to do it.
The most significant impacts may be
The degree of the impact will vary significantly by frequency. As frequency increases and wavelength decreases, the "holes" in the shield appear increasingly large. This is why high frequency cables often include foil shields, or even better, solid copper.
The total loss should be specified in the datasheet, usually in decibels per unit length, at several frequencies. Though for cheap Chineese cable there may be no datasheet, and even if there is one it may not be trustworthy.
If this coax is bundled near other cables or sources of noise, more of that outside noise will couple into the signal. More of the signal within the coax will get out, which you may regard as loss; or from the perspective of other signals, noise.
Whether this matters to you or not depends on your application.
In a receive application, loss is not much of a concern since both signal and noise received by the antenna are attenuated equally, and thus the signal to noise ratio remains unchanged. Unless of course the loss is so much that the signal is attenuated below the receiver's sensitivity.
In a transmit application loss can matter quite a lot. It is in many circumstances more economical to install a higher quality feedline with less loss than it is to install a higher power transmitter to overcome feedline loss.
The significance of common-mode ingress depends very much on your situation. The received signal from the antenna will already contain noise. Are there sources of common-mode noise that are significant in comparison? Is minimizing radiation from the cable a requirement? There is no general answer to these questions.