The practical implications are, that if you get in any kind of trouble that would usually ruin your vacations, they might now ruin your life.
You have been warned NOT to visit Russia and informed, that you might not receive necessary consular support in case you get into trouble. This means that:
If you get arrested, you can't count on the consulate providing you legal assistance, translation services, or negotiating with Russia to transfer you to the prison in your country in case you got sentenced. You might not get an international attention in case your process is not fair, which in current situation, would be unlikely to influence Russia in any way.
Note that it does not necessarily mean you being arrested because of political reason, for example to be used as hostage for exchange. It wouldn't actually be the worst scenario. The worst scenario would be to arrest you for doing some crime the police is unable or unwilling to solve and they just got for easy pray to get their credits. If you don't understand the language, you will be effectively left without any option for defense (in worst case, you won't get any attorney speaking your language and you won't be able to request one because of language barrier).
A more trivial case is being mugged. It's normally not a death sentence, but if you're stranded abroad, not knowing anyone, a consulate might be an only option to get necessary financial means to return home. Without that possibility, you might end up as homeless on the street.
Don't forget that warnings not to visit a particular country or evacuate ASAP might precede diplomatic measures that would put the citizens of the country in grave danger, like breaking diplomatic contacts or fully closing the borders. You might end up without having any possibility to leave the country, without any financial means and any possibility to find any job. Once again, welcome in the hotel under the bridge.
So if you want to go anyway, you should at least make sure you have a local contact that would be able to provide you financial and legal help (at least in the form of translation service) in case you get into trouble.