I hear what you’re saying and I hear and read it more often that people mention that platinum feels heavy on the wrist.
In absolute numbers a pt version will be heavier than a gold one due to the higher density of the metal.
But I own several platinum watches and truth be told, I’ve never “experienced” them as being* heavy or uncomfortable.
What I do notice is the sensation of wearing such a precious metal. It’s hard to describe as it is purely emotional but it gives me a, by lack of better word, “rich” feeling to wear them