I mean Russia definitely keeps losing very many soldiers every day, I don't think that is comparable at all. It's completely different from US vs Iran.
Rome lost loads of soldiers in the Germanic wars too. The parallel is that these wars are too expensive (for a non-existential conflict) to take to fulfilment, but also can't easily be disengaged from.
I guess it depends on what you mean by "easily", but Putin could very much just say "fuck this" and turn off the war machine in one day and it's not at all clear to me that there would be much consequential blowback other than the personal humiliation of one man.
Would other countries now decide to attack Russia? Of course not. Would the oligarchs flip out and have him assassinated? No. Would the West disassemble the sanctioning apparatus? Eventually.
But the real downside is just simple humiliation and to prevent that, they will continue sacrificing young men.
The only sources I can find for that are all Russian. Wikipedia (Which I assume you will dismiss out of hand) says it's complicated to determine at best, as they both hide information and boost propaganda. At least don't state it as fact. No one actually knows, which is why citing sources is helpful so that weight can be added.
I mean I guess I disagree with the fact that it has any truth about being a "special military operation", when it is really an invasion where a country is trying to gain territory using ground forces etc. It's an invasion and a war, they wanted the binary outcome, they just didn't expect the opponent to push back so strongly.