They always were. Even when Spock was using them, he only used them when there was no other choice, and even then, there was no generally no small risk to both parties.

From Enterprise, mind melds are treated as something both sensitive and private. Things you do with someone you trust. That seems to have carried over in the intervening centuries, but you're still not meant to meld with everything willy-nilly.

Because it IS dangerous. Trek lore has established that mind melds carry the risk of neurological damage, emotional overload, and Panar Syndrome in the melder.

And even if all of those risks are mitigated, mind-melds are incredibly personal and Vulcans don't engage in them flippantly.

Mind melds are overused and treated too lightly and simply by modern trek. I actually like Voyager’s take on it.

Enterprise has a mind meld rape causing a disease for T’Pol so VOY isn’t the only series with bad mind meld juju.

Mind melds are like unprotected sex. Fine to be done with a trusted partner, not something you want to do a lot with randos

• The mind is usually considered a private area. Most people want their thoughts to themselves under most circumstances.
• Also, this stuff actually predates VOY; In TNG’s “Sarek”, Sarek is hesitant to mind-meld with Picard to temporarily treat his Bendii syndrome.
• On a random note, my history teacher had this as a poster on her wall:

Because Tuvok, and the rest of the crew, esp Janeway, lacked anything resembling ethics or scruples.