With regards to how slow Adventure games can be, what I always loved in MI and others were those puzzles where you were basically stuck in a limited space and your options/solutions were also limited, but you were comforted in the fact that everything you needed is there.
On the smallest scale, it would be the Phatt Island jail or LeChuck's torture chamber and on the larger side, you have LeChuck's ship from Return, a relatively smaller space when compared to the rest of the game. Those help break up the game a bit and reward the players with a different type of difficulty.
When the game truly opens up with multiple islands, I really feel a sense of epicness and cinematic action, but one that I control as go from island to island and explore. So much better and more immersive than a huge cutscene or a quick time event in my opinion. Even as I get stuck, there is still so much to try and places to go, npcs to meet with funny dialogue, etc. For me, when you were limited to a smaller but still big space like an entire island, that's when my frustration can start churning up if I get stuck because I'm constantly going through the same island and characters. I think for this reason, LeChuck's Revenge and Return struck a near perfect balance for me.
One last thing to note for smaller scenarios is a shout-out to Tales, because I loved the puzzle/sequence of fighting Morgan at the start of episode 2. It was a puzzle, but wrapped in an action sequence that I never tired of watching, which was also partially because just having a genuine swordfight and seeing Guybrush being an actual badass was awesome as well. I love that type of puzzle format as well. The crazy escalation in episodes 4 and 5, with twist upon twist, was also peak MI storytelling for me and I became so invested, that I didn't care if I got stuck on a puzzle.
And of course the brilliance of Return, in that there is this large, overarching story, but also all these details that are there for you to connect the dots. A story not dictated to you, but partially told with the rest of the puzzles scattered for you to put together. It makes the environment and characters another puzzle/piece of the story for you to connect. This also increases replayability as you go through again and pick up on additional details you didn't notice before because you didn't have the context of the ending or other story beats and sequences throughout the game.
So, for me, I think the amount of locations open to the player, as well as those more limited scenarios, along with how dynamic the story beats are, always went a long way to make me feel like I was still progressing even when stuck because I was still moving through various locations or going through different scenarios.