This is my biggest flaw with Silksong. The bosses scale well throughout the game (The Last Judge in Act 1 -> Grand Mother Silk in Act 2 -> Lost Lace in Act 3 - a solid progression). However, the game takes a massive difficulty spike whenever you have to handle hordes of enemies in a row. I find this especially frustrating when it's incorporated before a boss fight starts, as it begins to test my patience. The biggest examples are the High Halls Gauntlet Battle, which was probably the most challenging section in Act 2 or Act 1, and felt substantially harder than Clockwork Dancers or, frankly, any boss beforehand. Then, in Act 3, the Coral Towers enemy gauntlet (which you complete to get the Heart of Might) almost made me drop the game - the game wanted too much endurance, and it's not fun to have to spend 10 minutes refighting easy enemies to get to the actual challenging wave of enemies.
As a player, coordinating against several game AIs with wildly varying behavior while also being able to take on these enemies is too much of a mental load within a one-second timeframe. The player is required to take extremely slow and defensive strategies (i.e., walljump to the top of the screen, throw out a charger attack at a couple of flying/grounded enemies, then run to the other side of the arena and repeat). This kills the pace of the fights, and if the player makes a mistake, it is very tempting to try and get in a couple of extra hits so you can move onto the next enemy wave and get back to where you were. My memory of Hollow Knight is a bit fuzzy, but I don't remember struggling nearly as much when there were enemy gauntlets. A part of this may stem from the double damage from enemies; a hit hurts more when you can only afford 2-3 mistakes.