The slackware Linux distribution has become famous because it provides a minimum Linux system. It's possible to install the software without the X window system and without programming tools. This will safe a lot of space on the harddrive:
https://www.linuxquestions.org/questions/slackware-14/new-minimal-install-of-slackware-14-2-a-4175586921/
But, even a minimal Slackware installation will need too much space. The base system needs 600 MB and if the X window system plus some basic apps are needed the user needs a harddrive with more than 2 gb. The advantage over a modern Fedora Distribution is not very huge. A complete Fedora Linux which includes Gnome, Tex, Gnu compiler and lots of other programs needs only 15 GB in total. So the basic question is: why does a Slackware system needs 600 MB and more?
It has to do with modern software development. It is working with libraries, with the Gnu Compiler collection and with the Linux kernel. All of these technques are using a lot of discspace. For example, in a normal Linux distribution the directory for all the libraries will take around 2 GB of discspace.
The good news is, that a powerful alternative is available over Linux, it is called Forth. A Forth system in the year 2020 needs the same amount of discspace like a Forth system 30 years ago. In most cases, it will fit in under 100 kb. The disadvantage of Forth is, that it's more complicated to learn. The reason is, that Forth is less documented than Linux and the amount of libraries is low. The advantage is, that Forth provides software which looks different from Slackware Linux. Forth has much in common with the early MS-DOS operating system which consists of 3 files and fits on a single 3.5 floppy disc. The main strength of Forth is, that it's hard to write bloatware. All existing forth programs are very small.