During this time, many casual, non-technical, or new users

were discouraged from using Bitcoin entirely.
I don't see anywhere that casual and non-technical, or new users, are discouraged from using Bitcoin entirely, most of these new users are even excited about using Bitcoin for their online transactions for the first time. And the next statement clearly contradicts the prior statement because as your next statement states that KYC and AML regulations failed to halt Bitcoin adoption, and even made the BTC ecosystem adapt with a centralized system.
However, strict KYC and AML regulations have not halted Bitcoin adoption. BTC has evolved into a dual natured @ ecosystem.
We can be thankful to centralized exchanges for promoting Bitcoin for their own interest. With this, even with the strict implementation of KYC and AML, people still adopt and buy Bitcoin through their services.
This dichotomy reflects the inherent flexibility of Bitcoin’s design,
which accommodates both regulated participation and decentralized autonomy. This dynamic continues to shape the Bitcoin ecosystem, making it a more structured yet resilient
landscape.
It is not that Bitcoin is flexible but rather the system outside the decentralized Bitcoin blockchain is able to adopt Bitcoin by implementing a system that can integrate centralized services ontop of the decentralized Bitcoin. As a matter of fact, Bitcoin is far from being flexible. It is the system outside Bitcoin that is being flexible.