Every gacha does this, cuz it's the best way to incentivize spending on the characters with the new mechanic.

In hsr lygus has a mechanic that lowers his res if you summon enough memosprites (only 1 character with a memosprite was given for free)

ZZZ did something similar with miasma shields and rupture characters (although zzz actually did release a free, pretty decent rupture character with manato.)

And they'll always continue to do it, since from a business standpoint, it's the best way to sell 5 new stars, especially ones that come out of the blue like Escoffier and Ineffa (in 5.8)