Wow, that’s big, congratulations! 
I hope we will see much more of this being driven by this new funding. 
I’m not sure what your own user data (interviews, etc.) say, but I have not known many people who would describe using Discourse as “fun”. Frictionless? Maybe, for some subset of users. “Simplest”? Mm, again, not so sure about that. Certainly not simplest to setup/install (I recognize that, given the tech stack, it may already be about as simple as it can be). But even from a user perspective you can see plenty of people here in Meta - and elsewhere - talking about Discourse seeming more “techie”, or even “complicated”, than some other related platforms/tools with similar goals to Discourse.
Now I know that specific suggestions around these broader topics and concerns are the best way to advocate for change (or at least the easiest for the team to engage with). And I will continue to try to do that as time and brainpower allow. But I also think it is reasonable to ask that a company of your size, with deep expertise in its problem domain, be more clearly responsible for translating general examples of user need or concerns into more specific features and other changes.
Ideally this would be not just through dialog here in the forums (which already happens, though with some concerns), but also through direct user (and prospective user/admin!) interviews with open and experientially-oriented questions (i.e. classic user interviews). I imagine you already do that give your size and experience, but if so, I think bringing some of that more open approach into Meta would be good. I.e. more of the Discourse team visibly doing the job of translating user sentiment and behavior into features and other changes based on openly expressed feedback.
By “visibly” I mean fewer responses from the team that put the responsibility on the user to make some specific suggestion and more of e.g. asking “What if there was X feature, would that help with your need?”
This, I think, is particularly exciting, and also relies heavily on addressing the concerns I mentioned above.
You know, of course, that my comments are meant respectfully and that I want the best for Discourse. And I also do not mean to suggest that you do not do user interviews, or that you don’t do any of the work of breaking down more general ideas and needs into feature requests, etc. In fact, I think there are visible improvements in these areas here across Meta over the last year or two at the least (I haven’t been around longer than that). Still, as an end user and administrator of several Discourse forums, my lived experience here in the forums trying to advocate for changes often seems to be met with “You’re not being specific enough” or “do a mockup” (which can easily be seen, depending on the level of capability and understanding of the requester, as “please do some of the development work for us”). You benefit from a high level of user skill here in Meta, certainly, but you cannot take that for granted, especially if you hope to “reach totally new audiences”.
I hope you don’t mind me raising those concerns here. I don’t mean to “steal your thunder”, but these concerns do seem relevant to this big increase in resources for the team. Thank you for listening.
Overall all I think Discourse is doing a great job. It’s an excellent product, with a thoughtful and capable team behind it, and this latest funding is well-deserved!