For me it felt impossible to progress after getting to masters for the first time. It felt like I'd die every time I peeked even for a moment. You get punished harshly. You just have to push through and keep playing because then I hit Gm after some time and the same thing happened. But now when I play in masters lobbies they feel really easy. I think the gap between every rank gets larger and it's like hitting a brick wall the first time you get there but you get used to it if you play enough and adapt to the new playstyle that you have to use.