Does software performance still matter?

Lots depends on where the bottlenecks are.

For a long time I've been building systems that do custom inkjet printing, like business cards that all have a different QR code. The printer is pretty slow and it has some feeding problems (cheap printer, old house with uncontrolled humidity, ...) so there are manual steps like I print the low-ink side of a batch of 20 cards, look to see if any of them are blank because the printer pulled two cards, put them back in the feeder, and if the printer runs out of sheets because of a double-feed take compensating action.

I don't have a lot of motivation to speed up the image generation process in that case.

I am now printing flyers on a laser that can print 30 pages per minute. Now I guess it wouldn't ruin my life to be printing these at 5 pages per minute but I'm definitely pumped at the thought of getting my code to match the performance of the machine.