HCB used 90 f4, not as much as 35 and 50, but he always kept it with him. Later HCB was seen in Paris with 90mm, it was an article about UK-French couple he took back then. 90mm lens has very shallow DoF.
Some old Magnum photogs still using Leica, younger photographers not so much. If you are into decisive moment photography you need to be rich kid as HCB was, or poor and eager as GW was. These days kids wants office and buy Leica for status at forums.
More expensive Leica gear gets more utterly boring and giftless photography comes. I don't blame those who takes photos like this.
To be able to buy 10k+ single camera, lens kit you need to be successful in money making, not in photography of decisive moment.
Good Leica photographers I have seen and chat with are using used film M and LTM and not expensive lenses.
But with 1.2 lens decisive moment is simple, it is the moment you have it in focus.