How do I avoid web app pagination / infinite scrolling

I develop web apps in various languages and lately I came across this problem.

My boss and the web app's users want a page without pagination or infinite scroll.

I try to tell them that user experience will be bad because of the loading time. And they answer me with: but Excel cand do that very easy.

They want web apps to behave just like an Excel sheet, with instant sorting, filtering and scrolling.

But one page can have thousands of rows with 20 columns or so.

Is there a way to design web apps that behave like Excel? All the users are used with Excel sheets only.

Thank you.