(and as long as there is at least one actor interested in RTT, and this actor happens to controlling both endpoints for a significant amount of traffic crossing the internet (Chrome/Google), there will be good mix of connections with and without spinbit)
> Even when the spin bit is not disabled by the administrator, implementations MUST disable the spin bit for a given connection with a certain likelihood. The random selection process SHOULD be designed such that on average the spin bit is disabled for at least one eighth of network paths.
[1] https://tools.ietf.org/html/draft-ietf-quic-transport-23#sec...