>> Often you will get a request, sometimes (or quite often) you have no idea what is driving it, like for example "reduce rate limiting for xyz service."

At my company, we do not allow tickets that prescribe a solution. A ticket can only describe a problem or a need. The engineer is then responsible for starting a conversation with the stakeholder(s) to discuss which solution might work better for them. They then implement that solution.

I know that larger companies have multiple teams that sometimes create tickets in each others' queues. I think this is a mistake. In multi-team environments, requests should go through some sort of custodian or gatekeeper who is responsible for making sure the problem or need are documented fully. This person can be a product manager or a scrum master. It should not be an engineer, though.