Before the first lockdown, one of my groups was suddenly running into some issues playing together. One player admitted to me afterwards that he had a panic attack during a game and another player admitted being uncomfortable and unsure about dealing with a somewhat confrontational player at the table. We’d been playing for a couple years without any safety tools. When I mentioned things like the X-card and Lines & Veils as options to help avoid any future problems at the table, they were very much on board.
Of course, we have yet to try it out as we haven’t played in more than six months. Sad face emoji with a single tear.
Where I’m going with this is that safety tools are great trust mechanics but they can also be helpful for other reasons. The player with the panic attack has no idea why it happened; having one of those tools available made them feel more comfortable to rejoin the group (he almost dropped out entirely that night) knowing there was something he could turn to a mechanic in the game if it happened again.