First off welcome aboard. Secondly on your collecting question I've fallen back to the same reason a dog licks it's @!#*&, because it can as my justification.
As has been said, it’s depends on the person and in my case, there are several layers. One is an interest in the hardware, especially razors. I just really appreciate the variety of design aimed at a single problem. The fact that user-grade vintage gear is so affordable makes it almost an afterthought to those of us fortunate enough to have the disposable income for a collecting hobby. The other layer is honing a skill, albeit a fairly pedestrian one but one that brings enjoyment nonetheless. I like trying new things and learning how best to use them. There are lots of hobbies that are way more expensive. I took up flying airplanes when I was in my early 30s for no other reason than I wanted to and I could. I have never had a collecting hobby so this urge to accumulate things is a new concern to me. I’m thankful that it’s inexpensive and lightheaded. I have a tendency to obsess and take things too far but from what I can tell, I’m in good company in that regard.
Unlike vintage wood working tools, a razor collection can still be large and fit in a single box. Edit: a shoebox, then a contractor tub.
I’m not a collector, I’m a user. I only buy what I plan to use. Sometimes I plan to use things for a long time.