Which is you go-to product analytics tool?

Moengage is not for Product Analytics sir. It is a customer engagement platform.

Switched to posthog. Very cheap in terms of costs, and quite customizable

There are different types of analytics and tools are toolboxes to achieve the same. Eg. Observability products have datadog, elastic etc, action based analytics with instrumention which can be used with any sql based tool (metabase etc) or statistical tools (python based notebooks running models etc). I think of Amplitude, Moengage as CRM++ tools where they track certain activities and you can define user journeys basis the same. The end objective from them is to derive the next action from the user. Analytics from them is just an enabler to reach the end goal. In the highly evolved organisations, leadership buys the tools basis data strategy (building data lake, enabling models, running A/B tests) and in slightly less evolved organisations, tools are bought basis price and problem at hand with focus on survival than strategy. AI is just a PR stunt in such orgs.

Using metabase currently. But do mixpanel/amplitude/posthog offer the same sql writing and DB building like metabase does?

Superset Open source and good tool for playing with Backend data