My personal objective with CRM is always the sales/cs team productivity at different stages and I don’t see the impact of your product yet on that. Every sales or CS agent needs to know what is their next task: they shouldn’t go through the list of the deals or customers to figure that out. Ideally they get their tasks assigned in some round robin algorithm taking into account their availability and skills. If agents nevertheless work with lists, they are going to create several dozens of views filtering certain stages of journeys and build up arcane knowledge on how to look at them. Not great, but if they want it, it must work - they are stakeholders in CRM purchasing process. Overall CRM must be customizable on tasks and journeys level, not just on record field level.
Do you need Apex for that? God, please, no. Apex doubles or triples the cost of Salesforce, because you usually end up spending tens of thousands euro on some agency doing the customization. If you want to compete with SF, offer Java, JavaScript or TypeScript as lambda or managed microservice hosting with fast links to your db/api (and do it better than Heroku). The better are your integration options with custom code, the more attractive it will be for digital services and non-trivial use cases.
I would love to see proper communication management respecting user subscription preferences and consent. Maybe look at Braze for that. If you could handle the calls, both inbound and outbound, internationally and with power dialer that would be awesome.