I remember the day when the same thing was said about chess.com - a site already very liquid, with many players -, I mean the lack of titled players, especially GMs.
By then titled players, truly big name GMs were all playing at ICC. Chess.com was not recognized as a serious place by then.
I think any site which has considerable and growing number of followers will sooner or later be recognized by titled players and they will start playing on that site.
The same is true for Lichess. The key whether it can attract a truly large number of players, if so then titled players will come along automatically.
By then titled players, truly big name GMs were all playing at ICC. Chess.com was not recognized as a serious place by then.
I think any site which has considerable and growing number of followers will sooner or later be recognized by titled players and they will start playing on that site.
The same is true for Lichess. The key whether it can attract a truly large number of players, if so then titled players will come along automatically.