They used to have 45/45. It was not very popular.
There was a blog post back in 2017 by CEO Erik giving some data on the popularity of the various time controls. He was surprised that none of the controls with increment were popular.
https://www.chess.com/article/view/interesting-chess-data-time-controls-and-game-results
The slowest time control 30 0 got only 2.9% of the games.
I suspect it is the same on lichess. The slow time controls make up a tiny portion of the actual games played.
How is it possible that on Chess.com, which is the biggest chess playing platform, it's much harder to find people who want to play longer rapid games or classical games? On Lichess' lobby area there are constantly players searching for longer games with increment. Could there be some kind of developement on Chess.com lobby or something? I've been wondering this same issue for years already; and can see I'm not the only one.
I mean, 60/0 is not a good way to play longer. It's tough to scramble an endgame, if opening and/or middle game burnt time. 60/10, 45/45, 30/20 or some other time control would be very useful among common time control options.