"Think once something is out of warranty, does it even matter? You can't really get service manuals anymore, most things are now surface mount and IC based. Almost no one can fix them anymore."
I don't think so. Much of the better hifi gear is still made with discrete components simply because there is still a contingent of designers and audiophiles that think they sound better. Also, more often than not discrete and surface mount are used in combination where engineers deem appropriate.
Vacuum tube hifi components which are extremely popular among a niche segment of the hobby are principally designed around discrete components and any tech worth his salt can troubleshoot them quite easily, repair them and restore them to original spec without any service documentation. Albeit there will be chassis components like transformers and such that are single sourced, likely a qualified tech can affect a repair on any other part of the circuit.
Luxman, McIntosh, Klipsch and other long-standing brands can provide or arrange to have any product they've ever made serviced and brought up to spec. You get what you pay for!