What are examples of functionality that people are looking for? Obviously they're not going to please everyone and I don't think (yet) they're trying to be LR II for people who don't like Adobe's subscriptions. That said, there are a fair number of LR people exploring C1 and are obviously wanting some of the comforts of home
As for whether to upgrade, for me, keeping my key software and hardware up to date is like car maintenance. It's already baked in to my yearly budget so I just do it. It's a drop in the bucket compared to most everything else. I also don't personally have a problem with software subscriptions.
Personally, I'm not looking for a one-stop shop. It's actually one of the numerous things I don't care for with LR, along with its (for me) speed, default rendering for my Nikon, Fuji and P1 files, module-based approach, hideous tethering, limited customizability and UI choices. For things like stacking or stitching, I prefer Helicon and PTGui as I feel they give me better results than one-stop-shop tools. I don't really do HDR but should I need to, Photopshop has worked great for me in the past and I've also used Photomatix Pro. Photoshop for pixel-based editing.
For C1, I want them to focus on improving noise reduction for when I need it, lens profiles, default rendering, diffraction correction, speed, better catalog performance for those who use them, etc. Continue improving color editing. Continue to improve layers. Continue to improve masking and brushing. I want an iOS/iPadOS version for easier tethering in the field and I want them to get going on an Apple silicon version. I'd like them to improve their plugin SDK and capability. It's pretty hideous to work with at present for those wanting to write a custom plugin. Those are things I can think of off the top of my head, in no particular order.
All of these things - the annoyances I find with LR and the things I do like and want continuous improvements on in C1 are simply personal preferences. Luckily there are plenty of choices in the market to find a tool that best suits how I wish to do things. Any tool can produce superb results in the right hands. This is a golden age of raw editors and photo editing in general. There's a choice for most tastes and budgets out there!