is NextDNS slowly dying or still have ambition for the future ?

From what you posted, this looks more like an intermittent resolver/path issue than evidence the service is “dying.”

NS_ERROR_NET_TIMEOUT_EXTERNAL generally points to a timeout reaching the resolver or upstream endpoint, not necessarily a dead platform. Since resolution still works most of the time, I’d lean more toward:

• regional POP/upstream instability,

• IPv6 transport issues,

• browser DoH timeout/fallback behavior,

• or temporary resolver reachability problems.

If NextDNS were actually collapsing as a service, I’d expect widespread outages, stale repos, broken billing/linking systems, expired certs, or long-term unresolved failures — not intermittent delays.

Also worth remembering modern DNS is messy now. Browsers, OSes, VPNs, and Secure DNS settings can all interfere with or bypass expected resolver behavior, which makes diagnosing these issues way less straightforward than “DNS server up/down.”