I’ve been thinking about this also.
Let’s pitch a scneario: maintaining a house. A person might collect various information about home maintenance and repair. A person also certainly has various tasks about repair on their house. There is a relationship between the tasks and the notes. I would find it useful to be able to see, “Oh hey, as I’m reading these notes about faucet repair for repairing the bathroom faucet, I see there’s also a task out there for the kitchen faucet” or some such.
Like OP, I’ve got a vast org-mode collection built up, including various tasks. I’m somewhat considering moving my tasks.org and similar into my roam directory and see how it goes. The good news is that I tend to aggressively archive done tasks, so they wouldn’t pollute the graph forever - and the pollution that does occur is likely relevant, though non-specific (since the #+TITLE of a file with dozens of tasks isn’t super specific)
More generally, org-mode and org-roam seem to inhabit two separate ecosystems; different assumptions about tags, relevance of section headings, etc… but they seem tantalizingly close as well.