If you're using Firefox you can set up a user chrome file -
https://www.userchrome.org/how-create-userchrome-css.html - and include this:
html, body { overflow: visible !important }
Most sites that disable scrolling like that have just put overflow: hidden on the html or body element.
To do the same thing in Chrome you can use a custom CSS extension. The thing I don't like about that is that you have to give the extension carte blanche in terms of permissions, and I don't trust that the extension won't be sold to a bad actor.