I mean I can imagine that if you have the tools to build those, you'd have a welder as well. Granted, welding might be a bit more challenging than cutting beams and drilling holes.
I would imagine that if wanted to weld it instead the design would also work for you.
A circular saw, a mag drill, and a stick welder could take you a long way on a project like this, and you could use regular steel plate, tube, angle bars, etc. I think a lot of cost and weight is being sacrificed in the name of "modularity", for questionable benefit.
If you need to, hypothetically, bury your society-bootstrapping supplies, your wrenches and hole bar will probably survive. But a welder may not.
Mind you, I've seen some... interesting welders cobbled together, I saw one that was a load of wire wrapped around a rubber inner tyre. Here [1] is one made from a microwave transformer.
[1] https://www.instructables.com/Build-a-Microwave-Transformer-...
General construction kit for real world applications. In theory you could take a machine apart and use the beams for some other machine. A smaller kit could build any of the machine designs as needed.
The problem with grid-beam is that it really only seems to make sense if you A) have lots of grid-beams in various sizes already, and B) are making, taking apart, and repurposing things frequently. Without A, making grid beams is a lot more work than just purpose-cutting your pieces, and without B, you don't really have a reason to drill all those extra holes.
The grid beam book talks a lot about what you need to make beams from scratch. You don't have to do that. You can buy (or print!) beams and get to work right away.
[1]: https://twitter.com/hugs/status/707381021646323712
[2]: https://www.mcmaster.com/8809T7-8809T21/
[3]: https://bitbeam.org/
I've been working to document everything I've done with Gridbeam, and related tech here: https://wiki.replimat.org/wiki/Main_Page
I lived with Phil and RJ Jergenson for a couple years around 2012, tried to learn from their experience and mistakes. They weren't happy with 1ft lengths in every project, even though they were an improvement in reusability over all lengths free-for-all. I've since moved all the replimat designs to use lengths 2, 3, 4, 5, 10, 15, 20, 25, and 30 only. Which allows for center pivots and divisible-by-two lengths whereas the Jergensons could only divide by two. We also hit countertop height a little better. Little tweaks.
I try to communicate with everyone listed in the "Friends" section on the right hand side of https://www.replimat.org/ regularly. I'm excited that things seem to be gathering steam for all of us.