I'm editing photos I took during my little holiday and thought I'd demonstrate something. (This is part of the Lovell telescope.)
Left: image converted from colour to b&w simply by right-click and 'desaturate': https://mastodon.art/media/3HvrgRnJaC1K2H8woew
Right: how I normally edit pics I want to turn b&w. https://mastodon.art/media/m55ScpjdRP_utXeV1Rg
Don't simply hit the desaturate filter! Take the time to play with levels, contrast, and even a bit of noise (blue channel) first.
I hope I'm not coming across as saying my method is the one true way or I'm an expert at this. It just disappoints when I see black and white photos that are clearly one-click when the OP could have made them so much prettier with little effort.