Seems so to me. Shifting was working perfectly all the way until the chain started skipping. When I installed a brand new chain and cassette, I did not notice any improvement. So if performance was degraded, clearly it would take someone more sophisticated than I am to detect it.

I also determined that babying a chain doesn't do any good for me on the foul weather bike. The route is so dirty that even with a brand new chain, within a mile of leaving home the chain is covered with grit and sand and clay anyway. I just oil it and wipe it down when it starts to make noise, and blast it with a power washer and relube it when it get so caked in mud that it won't bend anymore.

I once decided to try taking the chain off and cleaning in mineral spirits weekly (or when it was very dirty, whichever came first) and lubing carefully from the beginning with a new chain. The end result of spending what I would guess was easily more than 10 hours of my time doing chain maintenance (versus maybe 20 minutes otherwise) was that my chain lasted about 2000 miles instead of 1800 miles. That works out to about $1.50 worth of chain life, so I was working for about 15 cents an hour.

On my road bike I do clean and lube regularly, because it doesn't get ridden on the gravel roads (much, unless it's dry and clean) or in the rain, so the chain lasts longer.

On my new foul weather bike I expect the chain to last quite a long time because it's got an internally geared hub and a chain case, so the chain doesn't flex to the side.