StackOverflow Jobs was the best platform for finding and posting jobs: quality candidates, quality job postings.

I hope that whoever decided to kill it got a huge pay from LinkedIn/Indeed.

But it's loss would be felt for years to come.

And, who have any suggestions similar to StackOverflow Jobs?

There is none. Welcome to the hell of LinkedIn. You want a Java job? Be prepared to get offers for Scala, Azure DevOps and, for some reason, a ball bearings QA assurance and a gas station clerk.

I still need to understand the reasoning behind cancelling stack overflow jobs

No decent alternative whatsoever. They killed it because while devs liked it, companies didn't (because they couldn't spam candidates), so thought they could make more revenue through other streams like their new collectives.

Think it's fair to say, based on recent performance and layoffs, it's massively backfired. The platform has been going downhill for a while now (and not in this whimsical "it's not what it was" way, it's empirically losing visitors and engagement) - and the current CEO doesn't seem to understand what the platform is actually for. He'll run it into the ground to try to make any kind of profit, claim it as a success story, then move on.