The main reason is the build new packages and put on the repository.
I think this can be improved with a good tool to solve all dependencies and link all into a good package.
Today I tested the new Python version 3.5.10 released on September 5th, 2020.
I download an unzip the archive and I use these commands to build this python version
[mythcat@desk ~]$ cd Python-3.5.10/
[mythcat@desk Python-3.5.10]$ ./configure
checking build system type... x86_64-pc-linux-gnu
checking host system type... x86_64-pc-linux-gnu
checking for python3.5... no
checking for python3... python3
checking for --enable-universalsdk... no
...
The next command is make:
[mythcat@desk Python-3.5.10]$ make
gcc -pthread -c -Wno-unused-result -Wsign-compare -DNDEBUG -g -fwrapv -O3 -Wall -Wstrict-prototypes
-Werror=declaration-after-statement -I. -I./Include -DPy_BUILD_CORE -o Programs/python.o
./Programs/python.c
...
# On Darwin, always use the python version of the script, the shell
# version doesn't use the compiler customizations that are provided
# in python (_osx_support.py).
if test `uname -s` = Darwin; then \
cp python-config.py python-config; \
fi
Then I used make test.
[mythcat@desk Python-3.5.10]$ make test
running build
running build_ext
INFO: Can't locate Tcl/Tk libs and/or headers
Python build finished successfully!
...
For the last part I used this command:
[mythcat@desk Python-3.5.10]$ sudo make install
...
The result of this is ...
[mythcat@desk Python-3.5.10]$ ls
aclocal.m4 config.sub Include Mac Modules platform python README
build configure install-sh Makefile Objects Programs Python setup.py
config.guess configure.ac Lib Makefile.pre Parser pybuilddir.txt python-config Tools
config.log Doc libpython3.5m.a Makefile.pre.in PC pyconfig.h python-config.py
config.status Grammar LICENSE Misc PCbuild pyconfig.h.in python-gdb.py
[mythcat@desk Python-3.5.10]$ ./python
Python 3.5.10 (default, Sep 6 2020, 22:32:07)
[GCC 10.2.1 20200723 (Red Hat 10.2.1-1)] on linux
Type "help", "copyright", "credits" or "license" for more information.
...