I usually get unmanaged servers since I am able to manage my servers myself but I think when many speak of 24/7 support they are referring to emergency support not support for things like installing dependencies. Some also outright lie about it. Chances are if they only have one or two techs they aren't going to be able to offer 24/7 full general support. Most techs will resent getting paged at 3am on a holiday in order to install a memory upgrade or a custom ffmpeg. Unless they are getting paid very well.
More techs makes this easier to do.