The amount of time and effort spent avoiding this is laughable

Here the link to the created suggestion https://jira.atlassian.com/browse/BCLOUD-22181  for all those who voted here due to the "second motivation" to easily vote for the follow up.

We have reviewed the comments on this BCLOUD. The requests for Bitbucket Cloud to support a functionality to delete pull requests seem to be motivated by two primary reasons:

The first is regarding sensitive data being shown in a pull request diff. Customers who find sensitive data pushed into a pull request are looking for a way to remove this sensitive data by deleting the affected pull request.

We want to emphasize that deleting a pull request is not effective in this scenario, as the underlying commits containing sensitive data still exist in the repository and the sensitive data can still be accessed. The best thing to do in situations like this is to assume the data has been compromised. If these are passwords for example, it is recommended to rotate them.

There will of course be situations where you may not be able to take those steps, or you want to remove this data from the repository regardless. There are steps you can take to do that and we found that our existing documentation on this topic was not sufficient.

We have published a new tutorial which will walk you through the appropriate steps in these situations:

https://confluence.atlassian.com/bbkb/what-to-do-if-you-ve-committed-sensitive-data-to-a-bitbucket-cloud-repository-1168857188.html

The second motivation to delete pull requests is associated with administrative preferences to delete accidental or unnecessary pull requests. The current recommended workflow in Bitbucket Cloud is to decline these but we understand that some customers simply prefer to have these removed from their repositories altogether. To separate this specific feature request from concerns about sensitive data, we have created a new BCLOUD to track the feature request specifically for these reasons. We will gather your interest in this feature and we will evaluate it over time. In the short-term we do not plan to prioritize this feature as it currently does not align with our long-term roadmap. You can review our public roadmap here: https://www.atlassian.com/roadmap/cloud?selectedProduct=bitbucket

We are reviewing the comments provided in this ticket and we are working on remediation plan for the most common pain points shared in this ticket.

Perhaps a workaround could be forking your repo somewhere, then delete the original repo, then fork again from your forked repo. 

Sure it's coming.   Like the comet that will wipe out humanity.   We just don't know when it'll arrive, but unlikely in our lifetime.

Atlassian is a pile of s...shockingly poor decisions.

Is this coming?

It seems to be totally useless to write any comment to this request. The ticket has been created nearly 10 (in words: ten) years ago. I contacted the founders because of another request … they wrote back, that only very popular requests are processed. I cannot believe this. The issue was one of the top ten voted … created many years ago, not processed yet.

Maybe you should vote and pray …

I'm pretty shocked that it isn't possible to delete a PR. Beyond just wanting to keep cancelled or declined PR's pruned for tidiness, this does seem like a potential security risk if PII is accidentally revealed.

This seems to violate the GDPR right for erasure: Someone accidentally adds some personal information in a PR, and that's it. I find it quite disconcerting that a functionality so simple and relevant has not been implemented for such a long time.