So, instead of spamming all 3 charges you now spam just 2 and then wait for it to refill. At least on HFB the recharge of several seconds where you effectively daze yourself makes it basically never worth spending the last charge anyway. So all anet did was to take 1 charge away from anet and to make much more annoying if you ever accidentally "overstep" your charges. If using only 2 Charges is your idea of how mantras should be you could already just spend 2 charges and keep the third one.
There is a reason anet changed the mantras to a more straightforward system back in 2021.
GW2 already is one of the most complicated mainstream MMOs, any change that makes its baseline more accessible to newcomers is a good one.
While it probably does not attract people to the game it very much is what keeps them there. GW2 has no gear treadmill for ppl to grind on so instanced content is basically the only late-game activity in the game and if you look at how gatekept the GW2 raid scene is already we definitely don't need another thing for the newbie FB to worry about while learning to not get ported on his first ever VG clear.
While this Mantra change alone will probably not change that much for the individual player, it's another brick in the wall between a newbie and his first kill. Together with the other almost hostile changes to other beginner classes (for example mechanical genius' range paired with the mechs abysmal ai) the whole direction the game is moving in feels wrong to me.
Quo vadis, GW2?
PS: And credit where credit is due: There are some positive changes as well, like emboldened which gives first timers the confidence to just walk into a raidwing and give it a go.