To the OP: here is a suggestion. If you really want to understand what all "the numbers mean", you are going to have to dig deep and do a fair bit of homework.
Let's just say there are a lot of self proclaimed experts making youtube videos that are, shall we say, spreading information that I'm sure they think is correct. But it may be, less than accurate. I'll leave that at that.
Find accurate information written by engineers, and information on government websites to understand how GVWR and therefore payload, is determined, and why it is stated the way it is.
Come to a clear understanding of axle and tire load capacities. Those are important. Homework my friend, homework !
Hint: when you get to the bottom of this, I believe you will find your F150 to be a fine match for that trailer. Enjoy your camping trips.
This is an often argued ( vehemently argued ) subject on this forum. Dig deep and find facts. Try to look beyond internet forum hype.