Inhaling fumes from burning plant matter can't be good for your lungs though?

How can it not increase the chance of cancer (even if to a lesser degree) if you smoked as many joints as some people smoke cigarettes per day (of course you'd have other problems if you tried that)?

You're conflating legalization of Cannabis with the method of consumption.

But people won't smoke a pack of joints a day. Only, like, one per week or so.

Sorry but that is absolutely not true.

Has there been any advancement towards showing that it does? 10 years ago there was nothing, I know.

The person you're replying too is clearly just spreading FUD and probably has never partaken in their live - sad!

First hit on pubmed: https://pubmed.ncbi.nlm.nih.gov/23846283/

We know that just inhaling smoke from a wood fueled stove will increase lung cancer risk. What would be unique with Marijuana that makes their imperfectly burned plant particulates more safe than any other imperfectly burned plant matter?

The CDC view is also that all smoke from burning things is harmful to the lungs and can cause cancer, regardless of what is being burned. People with lung damage is strongly recommended to avoid getting into contact with smoke, including smoking Marijuana.