I'm a pretty avid fan of LoTR. And know what the Valar and Maia are. I post here by phone you know the deal.
And yes he did. He was at the Battle of helms deep. Are you saying Legolas and Gimli are not main characters? Frodo is not the only PoV in LoTR my guy.
And this is not the goddamn point. The point is, Gandalf was not the only fakeout death in LoTR. Faramir is too. Frodo "dies" like 3 times.
There are essentially zero major casualties in the actual fellowship outside of Boromir. Every person you mention save of Boromir and Theoden are essentially antagonists. Really? Gollum? Saruman? Grima? NOBODY else major in 3 books/3 films/whatever actually dies and has consequences. The fodder in the story take 99% of the damage.
Again. You are reading OP for the wrong reasons.
Gandalf's "return" in Helm's Deep was set up from the very beginning. He even tells them that he will return with the first sunlight on the fifth day. Him bringing back the Rohirim was also clearly foreshadowed. It was all set up.
Faramir never had a "fake death", because the reader always knew he was alive. Only Denethor was so crazy that he wanted to burn him alive.
That's completely different from Oda coming up with fake-tension and fake-death moments again and again.
And yes, from the "main protagonists" only Boromir dies in the LotR, but that was never the point.
Tolkin is at least consequent when he writes death scenes - with antagonists and secondary characters, too. He also killed Thorin and several other dwarves in the Hobbit and the vast majority of main protagonists in the Silmarillion btw.
With Frodo its the same. He writes scenes where its very critical, but never "fake death scenes". He always immediately clears up the actual status.