While Customer Success (CS) focuses on renewals to trigger the infinity loop, User Success (US) focuses on a different trigger: one initiated by the people using the products.
How is this done? Read on.

In B2B, the "customer" isn't necessarily the top influencer of renewals or churn. That's because the people in the role of "purchaser" are few in number, and might not even be users of the product. The real power in brand loyalty and influence comes from the vast number of users those purchasers were buying for.
In short, in B2B especially at Enterprise levels, [humans doing the using] far outnumber and far outweigh [customers doing the buying].
I've recently seen direct evidence of this. Before I arrived at a recent employer, I heard of an enterprise-level customer who had churned, and the reason had nothing to do with a failure on the part of any CSMs. The B2B customer realized that an unusually high number of people entering the workforce had experience with a different product. So, rather than spend time and money onboarding for the old product, they simply shed it and went with the new one that the incoming workforce of USERS already knew, en masse. Granted, this is an extreme example, but the root of my point is simple: higher adoption is a combination of easy guided onboarding as well as making the product itself more intuitive. (Neither one was done here.)
Potential User Success strategies you can apply:
Users, whether B2B or D2C, have an entirely different set of criteria you'll need to employ in order to approach them. I've led teams to be both empathetic and strategic towards both.
Guided onboarding
The stronger the product onboarding ecosystem, the faster time-to-success.
Reinforce with low-touch engagements
This is where a DCSM Team can shine. Many small-to-medium business (SMB) users manage things themselves. Like D2C independent users, they manage their own licensing, their own onboarding, and their own renewals. They don't always bring large ARR, so they don't often unlock full-scale enterprise CSM workflows.
Medium-touch engagements: hybrid handoffs
Mid-sized businesses may get CSMs, but only for purchases. They don't get the full-spread of enterprise-level training and enablement. Here's where a Digital CSM Team can leverage automated adoption for the mid-size client's staff/user base.

There's an inherent problem with LAER.
After arriving at a certain level of experience, many CSMs discover a common truth - something that keeps coming up in QBRs (B2B). Digital CSMs also notice it in reply-to emails and Community posts (D2C). It's called engagement fatigue.
Once a customer or a user goes through the Land and Adopt processes, they arrive at a tipping point - a threshold for tolerating sales, marketing, and even their assigned CSMs.
Example: If the software they bought is a creative tool, then the user simply needs time to play; time to actually be creative with the app.
We all know QBRs are where it's at, but at this point they don't want to be bothered by anyone. Thus, this is where CSMs notice their QBRs seem to grow stagnant. The parabola curve of adoption tapers off, and the next questions about expansion get "put off until later".
There is a fix. I call it LASER-Focus.
What's the "S" for? Success. Every customer in the history of customers expects to arrive at the success stage, and quickly. The slower the time-to-success, the higher the frustration. This model respects those expectations by adding a 2nd catalyst. This one gives the customer the freedom - and most importantly the time - to onboard at their own pace. The sentiment and the demeanor of our approach is very anti-LAER.
How get un-stuck from the Success Stage:
We don't just put them on a shelf and ignore them. We offer touch points throughout this stage. They can either respond to them or not, but once they've had time to play with the product on their own terms, we employ their participation to become a self-sufficient partner on their own product journey.
Bonus:
You can measure this through a very special modernization done to QBRs, health scores, and staff-facing EBRs.