I still use a 2015 MacBook Pro daily. (Also have an Apple Silicon MacBook but I keep the Intel-based one downstairs and pretty much just use it as a web browser.) It's had its battery replaced (and the screen replaced under warranty for a defect) but it's just fine for my needs.

The power issue is more with large desktop systems. I was setting up a moderately old but fairly hefty system as a file server. Couldn't get it working--which I discovered belatedly was an issue related to my network switch--so I bought an unpopulated Synology box. But, given power consumption, I also realized that was probably the more cost-effective thing to do anyway.