I do think that the relationship between Frodo and Sam is romantic, although I don't think Tolkien intended for it to be such or even maybe didn't see it as "homosexual". For all we know Tolkien might have had romantic feelings for men but just told himself it was friendship because of his religious beliefs. Jonathan Pelotti has a great article about Tolkien's connections to the queer community - his best friend was gay and Tolkien apparently knew this and didn't condemn him.

Why I think Frodo and Sam are more than friends:

In the books, Sam kisses Frodo's hand multiple times in an affectionate way (not a servant way), has Frodo lay his head in his lap while he strokes and cradles his face, is described when he fights Shelob as "like a small animal defending its *mate*". He was so distraught over Frodo's seeming death that he wanted to commit suicide and die with his body. That was his biggest wish.

This isn't just "men expressing platonic intimacy". I don't know of women that express that kind of intimacy while being "just friends". It goes beyond that.

There's a lot of platonic intimacy between other members of the fellowship too that aren't seen as gay - like Aragorn and Boromir for example, or Legolas and Gimli. Or Legolas and Aragorn. So it's not like people "just want to make male friends gay". It's something specific about Frodo and Sam that is coded as queer.

When Sam gets married, he and Rosie live with Frodo until his illness forces him to go to Valinor, almost like a polyamorous triad (without any overt sexuality since the entirety of LOTR is without overt sexuality). But it's clear always that the person Sam loves most in the world is Frodo, not Rosie.

Then the Appendix of the Lord of the Rings shows that after Sam's wife Rosie dies, he sails to Valinor to live eternally with Frodo in the Undying Lands. So he chooses to live "happily ever after" with Frodo over dying to be with his wife.

That's not normal platonic intimacy, no matter how you slice it. There may not be anything essentially sexual in it, but it's certainly what we would consider romantic.

That is why I think the queer reading of LOTR is valid. You can disagree with it, but the textual evidence is way way stronger than average "rainbow washing".