ProductOps is a specialized role that normalizes and helps scale the product function across all products and services.
Your teams have adopted numerous methods and roles. They have attempted to implement the same practices as described in that article or webinar, yet don't seem to get the same outcomes.
Why is it not working?
Because your organization is unique.
No other organization has the same teams, the same products, the same roles, the same constraints, and the same risk profiles.
What works for another company may or may not work for your team. Another team's "best practice" may not be appropriate for your team.
When a company is small, the product manager (by whatever title) is responsible for activities across the entire product life cycle—from ideation to market delivery and sales support. In these organizations, the product role is that of a generalist. And with one person, whatever works... works.