For what it's worth, barring catastrophic failure, which seems to be rare, these things tend to hold up quite well. My previous Macbook lasted me about 6 years, I had its battery replaced half a year ago without any issues; it's my backup machine now, and if it weren't a tad too sluggish at some tasks, I would have postponed the upgrade another year. Lots of people (on HN, too) run even older Macbooks, apparently happily.

Just be sure to get the latest gen, especially for the 13" Pros ones – you absolutely want the 2020 keyboard (physical ESC key, no failure-prone butterfly mechanics, really nice feel, "old" arrow key arrangement that is easier to find by feel) and the newest CPUs. I have both keyboards (my own 2020 one and my 2018 work laptop) and the difference is crazy. But as I mentioned before, have a look at the current Air as well – cheaper and still plenty powerful, depending on what you need.