Lost 164 pounds getting to my goal, not quite what you're aiming for but still over a hundred, figured I'd weigh in anyway. Calorie counting is what worked for me, and yes I brought it down gradually, but the lowest point was around 1260, only briefly. Once I tried reverse dieting for maintenance, realized that number had been too aggressive since I kept losing steadily even eating more. Realizing that 4-8 pounds every couple months counts as genuinely healthy progress, and even half that number is perfectly fine too, might be worth taking to heart. My loss pattern shifted a lot over time, often two or three weeks of barely any movement followed by a sudden bigger drop, which honestly helped me push through those little plateaus since I trusted the deficit was real and my body would eventually catch up.
On the activity side, around four months in I started feeling the pull to move more and began walking on purpose daily. Didn't connect it to the actual pounds coming off at the time, but overall it left me feeling noticeably better, and it's possible it played a role in the loss too. Definitely believe building that habit has helped me stay steady in maintenance. Eventually added strength training too, which honestly is the one thing I'd have started sooner if I could redo it.