I'm about 9 Kyu, at least back when I was practicing and reading every day.

I'd say that at 9 Kyu level, my main gains were playing and abusing Tenuki. Refusing to respond to the opponent's (weak) early game moves and instead playing significantly stronger elsewhere on the board.

If the opponent were stronger than me, I'd pay attention when they ignored my moves. Its actually very difficult IMO to play sente every time as a double-digit kyu (or even high-single digit kyu). Recognizing that the last move wasn't forcing and that playing elsewhere is a surprising way to get ahead.

Vs stronger opponents who can tell when the board is sente, gote, appropriate to Tenuki, and is able to count up Ko threats... well yeah. I lose. But there's significant skill in this part of the game and NOTHING in this set of tutorials that teaches it.