The claim that meditation can make you 10% happier is true, and also an attempt to be reasonable
The more interesting truth is that a deep, life-embracing spiritual practice can make you 2-3x happier
Measuring happiness on a linear scale, is, of course, a sucker's game, it works on a logarithmic scale
My life got twice as good when I stopped being suicidal, and then, twice as good AGAIN
Imagine if during the course of mundane experience you had the option to, no big deal, connect with the numinous majesty of being, and then just go back to being normal and eating a grilled cheese or whatever
It's a realistic possibility
As is seeing God in everyone around you
Of course there are lots of traps, you can drive yourself crazy on the way (I do not recommend a life of dry vipassana), you can use it as a cudgel against yourself, etcetera, and I don't think it's ever really "done"
But caveats aside: yeah
Many meditators will not talk about happiness on these terms because it turns out that a lot of this is about moving beyond the strategies that, by default, people use to make themselves happy
But straightforward happiness is part of the result (though not all of it)
idk if im happier now, but i feel deeper? like my resting set point feels roughly similar to where it was before (maybe a bit better), but i feel significantly more at peace/vast/safe