I've often felt the same way; I've read some of these and (think I) can spot people using those learned things a mile away, and it immediately raises my hackles up. Management and sales people especially. Touch my shoulder or try to shake my hand palm-down just raise alarm bells.

But that's the other side of these books, understanding "the other side" of people.

I like to believe it all adds up to a big pile of knowledge that finds its place in one's personality / outwards behaviour. But to more observant, introspective, overthinking, possibly neurodiverse people, it just adds to a giant pile of social behaviours that some people seem to have naturally while others have learned / are forcing them.

Doing them costs me energy and makes me feel underhanded / ungenuine. At the same time maybe doing it more often will make them feel natural? I have no idea.