“ hydrogen in the universe create an obscuration effect similar to the way air does at great distances?”
Ask the one who looked, not the one who didn’t.
Ultraviolet astronomy was (effectively) unfunded, at least by mega-funders, because enough people suspected the interstellar medium (galactic gas, overwhelmingly hydrogen) would just result in a “fog” at those wavelengths- certain hydrogen lines, which are largely in the UV. (This did not stop solar and planetary UV astronomy, since solar illumination is good, and distances are irrelevant for the interstellar medium.)
At some point, someone with decent enough resources did a UV program, and found… no fog, really. The interstellar medium, as embodied as hydrogen gas, forms a “cirrus”- patchy and wispy. Plenty of things are visible, even in the UV, where the hydrogen just so happens to be thinner, not thicker. Even in some arbitrarily-dense regions of hydrogen, a fine enough spatial resolution (“high magnification”) decreases the background level, but does not decrease point sources (e. g., stars). A well-planned observing program then experiences a worse signal-to-noise ratio, but may be able to continue anyway, depending.
And of course, this is in UV- hydrogen has no strong lines in vis. If you want to get pedantic, you can even do UV astronomy by exploiting wavelengths between the H wavelengths, though in some spectral regions this will mean seriously expensive filters, with serious discrimination.
We can repeat this exercise for dust. Dust is primarily an issue in infrared, both due to self-emission (thermal) and the inherent size of particles. Depending on the details of your observation, the dust will be relevant or irrelevant. This includes those looking at the dust itself .
Vague, ill-posed questions get vague, inconclusive answers. What is your target, what is your hypothesis/null hypothesis, what is your observing plan, and your (baseline) instrument? For a given line of investigation, a better question is whether your instrument will answer that particular question, or whether you need more funding to produce a significant result (including any non-vague answer). The notion that things are “invisible/visible” presumes a particular eye, observer, etc. Not a telescope technology, a program with a given resource level, or possibly an observer with a new approach.
The history of astronomy is littered with people who “saw the light” after they tried a new way (though, more and more these days, that means trying to win more funding). The notion of “invisible” (and thanks for saying “obscuration” instead) is vague and ill-posed, based on arbitrary human sensory and perceptive ability.