Something that comes up time and again is the complaint about using old software. A classic example is the Xorg vs Wayland debate.
This fallacy is the claim that because the Initial Release Date is earlier, that it must therefor need replacing.
This is a fallacy because much of the software we use today is not only old, but older and undergoes persistent maintenance and evolution.
It also is a fallacy in that if something is to replace it; it must bring the same functionality, not rely on the old system it is replacing and improve the performance. Wayland utterly fails the first two and the third is situational dependent.
Importantly, we should examine whether age is an actual factor.
Everything listed below is active presently, currently maintained and currently evolving. Name followed by initial release date:
C 1972
Fortran 1957
COBOL 1959
Perl 1987
GCC 1987
MIDI 1983
LaTeX 1985
SQLite 2000
Vi 1976
Vim 1991
Emacs 1976
Bash 1989
MATLAB 1984
PGP 1991
OpenSSL 1998
Apache HTTP 1995
BIND (DNS) 1983
OpenSSH 1999
Postfix 1997
Sendmail 1983
BSD Unix 1977
Linux kernel 1991
Modern Windows NT kernel 1993
OpenVPN 2001
Kerberos 1983
Lisp 1958 (used to develop A.I. today)
CDE 1993
Audacity 1999
GIMP 1995
Blender 1995
DOS 1981
IBM AS 1988
OpenBSD 1996
Being old does not mean outdated, defunct, irrelevant or abandoned.
This list can get a whole lot longer should I really have gone out and made it so. The vast majority of the software the average daily users relies on is much older than they think it is.
And there is a great deal that the average user does not see; does not use themselves, but rely on heavily once we start listing that which is used for databases, scientific, governmental, utility and military. That list would dwarf this one above.