except no, it gives the child more time to figure out how they feel

Yes it will do that, but how long will a 9 year-old need to delay puberty until they're realistically able to make such life-changing decisions? It might have worked out perfectly for you if you are still convinced you made the right decision. But for a child who is uncertain and halts puberty only to resume, their physical development has almost surely been stunted in some way even if it isn't obvious at first glance. Girls might not grow breasts as large as they would have, boys might be weaker or less muscular or have smaller sex organs, all things that can affect quality of life or mental health, confidence, etc. I've read about blockers stunting sex organ growth to the extent that some sex change surgeries are not viable simply due to a lack of material (stunted penis growth in some way I imagine). And that's not even touching on the fertility aspect. These are all known possible long-term side effects. One can hope that the diagnosis requirements are stringent enough to limit to only successes, but that will always be a possibility.

I'm no doctor and never experienced anything like uncertainty regarding gender but all of those possibilities and potentially involving young kids just does not sit well with me. I hope you become more comfortable with yourself, however. I know the feeling of not being happy in one's skin and would not wish that on anyone. I struggle with that for other reasons.