Fastest way of viewing data from very large lists/libraries in SharePoint Online

Hello all,

We have a heavy site collection containing mostly documents and folders in a single document library (over 100 000 items). For this same library, we enabled content types and added many fields as custom metadata to both folder and document levels. We are currently using list/library views to display these items. Almost all list views are configured with filters. Our problem : We have "needy" users requesting more filter and more sorting possibilities in these views. We decided to stop forcing list views as they are getting really slow (takes almost 30 seconds to load a 1500 item page in modern list views). My question : What would be the best and fastest way to display data from this large library ? Custom dev ? SPFx webpart using Graph ? Are there any third party tools that we can potentially use to create a new data view experience ? Our main challenge is to display all this as fast as possible and with a good user experience (filtering, sorting, searching ...). We have already created a lot of indexed columns in this document library. Also, splitting the document library is not an option for now (We have business workflows running behind the scene in this document library). We are really getting out of options here. SharePoint storage capacity for documents is very good but the data view/display options are quiet lame. We can look into all options. Many thanks