If you ask people who more acquainted with metroidvanias it's not going to be topping their lists.
The satisfaction of feeling your set of abilities and options for gameplay increase and grant the ability to overcome previous obstacles is the main thing I expect and want from a Metroidvania. I felt like this was Hollow Knight's biggest weak point. It just didn't feel like you gained new abilities at as steady a pace or as though they opened up enough of the world each time compared to other games in the genre, including Ori and the Blind Forest. I think Super Metroid still has the best progression among Metroidvanias, but it's possible that's colored by my having first played it at a young age.
That being said, they are still very good games; excellent atmosphere, artwork and presentation, some genuinely haunting, creepy, and awe-inspiring areas. But I think Hollow Knight is a tier above them.
Personally I find combat to be one of the less important aspects of Metroidvanias. I prefer the main source of difficulty coming from platforming around environmental hazards.
I felt like exploration in Hollow Knight was a bit too broad, and lead to too much unnecessary backtracking. Backtracking is a balance. It's a staple of Metroidvanias, but if the backtracking search space is large enough and places aren't distinctive enough then the search for a previously insurmountable obstacle can start feeling like looking for a needle in a haystack. That was my experience in Hollow Knight, and something I felt like the first Ori game did better.