I've run into the problem a few times, trying to run an old version of a software for research purposes. But for daily usage, this misses the concept of open so

I've run into the problem a few times, trying to run an old version of a software for research purposes. But for daily usage, this misses the concept of open source. Most decades old software is still maintained, rebuild and packaged by every distribution. You can't easily run a 30 years old program, but you can run its latest version, for free.