I was recently researching the use of Material Design in iOS apps and came across this UpLabs article which makes an interesting point:
Various elements both visual and underline mechanics could certainly be incorporated into iOS apps.
However, it is important to stay true to the operating systems nature. Forcing a user to adapt or take on new sets of habits within a an app could cause great confusion.
It is important to intelligently incorporate various elements of Material Design but it is imperative not to confuse or undermine the user in the process.
For this reason, I would only consider using the Material Design guidelines in an iOS app where it does not conflict with the Apple Human Interface guidelines, unless the Material Design element provides a significant improvement to the end user. One such area is movement/animation, which in my experience is served much better by Material Design.
But when it comes to web, there are no general HID guidelines and as such users have fewer expectations.
Because they have fewer expectations, it's perfectly acceptable to mix and match guidelines to form the best experience for your users.