From what I can tell you, good security is hard - we have prepared the product exactly as you describe on various levels (vpn, identity, SSO, Yubikey provisioning, etc) and prepared the architecture to be secure (multiple segments support: intranet, DMZ, proxy for exposing only public endpoints and functionalities publicly)…
What I observe in a year of the project being public and analysing heavily the landscape, similar projects, Reddit of what users are seeking and what problems they have is that: a lot of people and companies value comfort more then security (even if they will not admit it publicly), because security is hard. That also means there is w niche and need, but… it’s really hard to build a secure, easy to use and deploy security system…
Hope you don’t give up and peruse!, as it’s worth fighting about security and privacy