I don't think superhero movies are in any way negatively impacting cinema. It is merely just another genre with it's own dedicated fanbase and fandoms. There are fans across different generations to whom superhero movies are close to their heart. And even during times like now when streaming movies at home are getting more popular compared to watching movies at a theatre, superhero movies still attract audiences to the theatres.

Now, you can say that it is just superhero movie formulas are hurting cinema by being repetitive when after a point almost everyone does the same thing again but there are genres of movies like romance or horror doing just the same. If you take romcoms, it it the same recycled boy meets girl story where you know what you're getting or the adult comedy movies with the same recycled "comedy". When you say superhero movies hurting cinemas this is inclusive of all genres all part of a business model meant to sell and make profit or even meant to flop for tax reasons of the production companies behind the movies.

more movies obviously will continue being produced as long as these crowds keep flocking to the theatres generating them profits. it's the same reason there are multiple sequels to horror movies being produced mindlessly, take Scream for example.