Are you going to stick to the topic, or will you continue with these diversionary tactics?
If you cannot explain the mechanism for gravity, then just say so and be done with it.
Newton did so.
The difference is he called people who believed in gravity to be people of low intellect.
You need to take that up with Newton.
You haven't even understood the Newton quote that you yourself produced. That's not what he said at all. He was in no doubt at all about gravity, indeed he used it to formulate his view on the shape of the earth. Spoiler alert: not flat.
His issue, which by the way was in the middle of becoming a 'formed view' at the time of the letter you quoted, was the manner which gravity was transmitted.
You seem to be obsessing about mechanism. We can have that discussion if you wish - you'll clearly dismiss anything we present, so it's probably pointless, but there you go. I see you've already dismissed LIGO without evidence.
But I think the broader point is that there doesn't need to be a mechanism. You don't need to know how magnets work to observe and measure magnetism. I don't have a the deep physics knowledge to fully comprehend it, and from my light reading of the matter, it sounds like it's not fully settled, although I gather photons, both real and virtual, are involved. But magnets clearly work. A lack of detail on the mechanism does not negate the existence of the force.
The same is true of gravity. It has been measured. Cavendish measured it. Lots of people have measured it and they are with 0.15% of each other for the gravitational constant. Why do you need a mechanism before you acknowledge that something is there?
And you haven't answered my other question - are you saying that water wouldn't adhere to the earth even if gravity existed, or are you saying it would stick but gravity doesn't exist? They are two very different arguments. Which one are you picking?