I think that we should take the OP's concerns seriously and not poke fun at him. There is no reason to be rude.
Having said that, I respectfully disagree with the idea that one's own black tank poses a significant health risk. Is there some risk? Perhaps, but it is a very small risk.
By contrast, using public restrooms poses a much greater risk -- some members of the public are very sloppy about personal hygiene.
Dumping the black tank does involve some risk, but that risk is easily mitigated with disposable gloves and hand sanitizer. During the height of the pandemic, we also wore masks when dumping the tanks. We no longer do so. Note that the dump station is outdoors, with great air circulation, unlike a public restroom.
Having our own traveling bathroom meant that we were able to travel during the pandemic without using public restrooms. Otherwise, we would have had to hide out at home.
I hope this whole discussion has helped to reassure the OP. Everything in life involves some risk. It helps to quantify that risk and to weigh the alternatives.
