I've been doing a project https://themildtake.com/articles/2026-07-04-a-declaration-of-independence/ ever since Independence Day and I have been shocked by how insane the open-source tooling out there is now. NextCloud and Collabara alone solves 90% of company's needs. ERPNEXT covers a huge swath in mid-range needs. I combine it with a mailcow server and Authentik for SSO and I am not sure how much else most businesses need. The whole stack is zero cost.