It's not me, it's the IETF, https://en.wikipedia.org/wiki/Internet_Engineering_Task_Forc....

QUIC is a standard, it will be stabilised in time.

TCP can't be improved on much at this point, and there are some pretty massive flaws in it that QUIC solves.

TCP isn't going away any time soon, or being "replaced" by QUIC, but for certain applications QUIC is going to be a massive improvement, albeit and an increased complexity and application size cost.

There are over 10 implementations of QUIC at this point in time, you don't have to go with Google's approach, https://en.wikipedia.org/wiki/QUIC#Source_code.