Yes it does! They are as you say big. They will eventually hit the explorer page or have enough engagement for their posts to be seen. Other than that big profiles have great networks. They tend to help eachother in order to reach a greater audience.
Also there is tricks to using hashtags. Do not be of that belief that big profiles don’t use hashtags. They do too. But they hide it pretty well. You see if their post gets 2000 comments, they can hide the hashtags easily in between all those comments making it hard for anyone to find. Unless you are willing to scrape all the comments to find the hashtags.
There is no rules written in stone that hashtags only has to be posted in caption. You can post them in comment section too.
Anyways. I believe you will get a really good insight by reading these threads and guidelines.
And don’t believe what others say before you try it out for yourself.