Wait until you have several books and want the equivalent of PDF's Ctrl+F. Or if you want to use the index that's in the printed copy. There are things I like about the D&DBeyond format, but it's much harder to use as a reference for something you only partly remember.
The fact that the Compendium category is a dumping ground for everything including adventure module text is incredibly frustrating the moment you start to search for something that you know is in a given book but you've forgotten which chapter.
Yeah, they need to improve search options. Bring in some AI to allow more effective natural language searches. Also have a rules reference with an alphatized index linking to rules accross multiple books. Finally, a feature that allows you to create your own DMs screen or reference article with easy ways to send content or cross-links to it as you review the rule books would be nice.
They've developed some nice new features in DDB, such as Maps, but they've done very little to improve the search and lookup features.
I still prefer searching in DDB than having multiple PDFs open and using CTRL+F.
Not that I've been playing Warhammer Fantasy RPG in Foundry, with all of the rule books in Foundry Journals, I find that the best of both worlds. I can search across all of my content. I can copy a link to just about every object, whether a journal, actor, item, roll table, etc. by clicking a button, or dragging it to a journal. And when I want to a PDF (e.g. there are some games where seeing things as they were formatted for print--especially some adventure material--is useful), I can embed that into a journal so I don't have to have a separate PDF reader open.
The one thing that I can't do is have the content of PDFs embedded in journals indexed and searchable for running searches across all content. I can search within a single, displayed PDF, but that content is not included in any "universal" search. But for WFRP, it doesn't really matter, because I already have that content in Journals. I just have the PDFs available when I want to see the original formatting.
Apparently, the Pathfinder 2e game system for foundry has modules that allow you to import a PDF and have it converted to Foundry journals. Apparently it works well. If more game systems in Foundry or other tools had such functionality I would be far more pro-PDF. Because PDF would then be a universal format that you could import into usable content into your VTT. But for now, in the systems I play, I would have to do it manually, which would be turning my hobby into an unpaid data-entry job.