Event-sourcing for multi-tenant B2B SaaS — genuinely worth it, or over-engineering for most teams?

My default architecture for multi-tenant B2B SaaS is event-sourced: commands produce immutable events, read models are projections you can rebuild anytime. Why I like it — audit trail, full history, and strict tenant isolation aren't features I bolt on later, they fall out of the model itself.

But I keep meeting sharp devs who think ES is over-engineering for most SaaS: more moving parts, eventual-consistency headaches, harder onboarding — and a plain CRUD + audit_log table would've shipped faster.

Genuinely trying to find the line, not defend a position:

• when is ES the right default vs a trap?
• what made you regret it (or regret NOT using it) on a real product?

Not selling anything — this is the reference architecture I keep reaching for and I want it stress-tested.