I changed my career 18 months ago and became a sysadmin. And forums like stack overflow are really important too me. But it took some time teaching myself to scan these forum topics and identify whether;
- The problem is really comparable to my problem.
- The answers are 'universal' or bound to the commenters workflow.
- The commenters explain their answer so I can actually expand my knowledge.
- The commenters interpretation of the problem is right or wrong.
Most of the time I open 8 'simular' topics, close 6 of them after scanning and then dive into the two I find most suitable.
About the scenarios you describe. Maybe different types of commenters are needed for a forum ecosystem. I can imagine someone spending more time writing a helpful comment after noticing the scenario's you describe. Maybe we need bad topics/comments so people with (writing/educational) experience step up to save the day.
Forums can be confusing in situations you describe but compared to closed communities like Discord it's something I cherish most on the internet.