When you keep having your post deleted or merged, I suggest you look within, that's the only way to get better. Try to see if it's a "you" problem. Always blaming someone else for everything won't help you, it only shows that you think you're too big to make a mistake or learn.
I have had 4 posts deleted since I joined the forum. 2 of those posts deserved to be deleted by moderators, but I can make a case for the other two. There was no point in me making a fuss out of it because all I needed to do was see how I could make better posts in such a way that they wouldn't get deleted.
Some sites like reddit, twitter, youtube etc are famous for becoming successful by overcontrolling members.
I don't know about YouTube and Facebook, but Reddit is very well moderated and that's the reason it is one of the few social media sites with less garbage. You can still have your opinion and support whatever you want there, but your post shouldn't be a load of rubbish or spam because it will get deleted. That's also why there are not many scammers there as they are on Facebook and Instagram.
So, don't see the deleting to merging of your post as a prejudice against you, see it as an area you can improve on. A merge post IMO is worse than a deleted post because it means you made more than one post that can easily be one post.