That can be true for self-contained command line tools, but not for complex programs with actively development dependencies (especially anything dealing with networking or encryption). For example hexchat uses GTK2 which is likely to be removed from mainstream distro repos in the coming years because it has been obsolete for a long time. Also openssl which is known to change its API occasionally which means that anything that uses it needs to be updated to stay compatible.
That can be true for self-contained command line tools, but not for complex programs with actively development dependencies (especially anything dealing with networking or encryption). For example hexchat uses GTK2 which is likely to be removed from mainstream distro repos in the coming years because it has been obsolete for a long time. Also openssl which is known to change its API occasionally which means that anything that uses it needs to be updated to stay compatible.