I had a near-identical experience (to OP) when flying LHR-YVR in CW last Jan (tired old 747, upper deck, half-empty, made to feel a nuisance for e.g. asking for red wine top-up when my meal arrived, then eventually having to go to galley to get it myself while they chatted and dawdled over trays, because I had specifically wanted it to go with the beef and there was no sign of it - just one example).
The relation to original post is to ask, is there any connection between 'less valued routes' and equipment/service (older planes, poorly-motivated crew, low passenger loads)? This occasion certainly felt like a 'poor relation' flight compared to LHR-JFK.