21 year old AV receiver - waiting for the end?

Since 2002 my Rotel RSX-1055 has been on almost every single day. It has never failed in well over 20,000 hours of running - maybe 30,000. My $1200 investment has worked out well (However, had I put this in Apple stock, it would be about 150k). I know that capacitors can dry out over time, so I looked into some preventive maintenance. Rotel’s answer was it’s not supported, they don’t have parts, and a local shop who does a lot of work on old amps, mostly tube stuff, says they don’t work on AV receivers. I doubt I can find anyone to do this. So my question is, what will the end look like? Is it likely to fade out one day? Will there be a faint sizzle sound, or smell of electronics frying? Or will I wake up one morning to find it has passed quietly in the night? How long could this thing last? I don’t want to give up on it.